“Mission Statement” (moved)
August 20, 2014 3:38 am
Bowel Obstruction After DS
August 20, 2014 12:47 am
One of the potential complications of any abdominal surgery is Bowel Obstruction. If the treating physician (usually the primary care, or the emergency room doctor) is not absolutely clear of the anatomy of a patent post duodenal Switch or the Gastric bypass surgeries this will pose a diagnostic dilemma. In intact anatomy the GI tract start at the mouth and ends up at the rectum as a long tube. After the Duodenal Switch the small bowel has two parallel limbs, the alimentary limb brings the food down from the stomach, and the biliopancreatic limb brings down the biliopancreatic secretions. These two limbs join and form the common channel.
In normal anatomy, bowel obstruction may present with nausea, vomiting, abdominal cramps, inability to pass gas, and/or have bowel movements. In this case, the X-ray will also show dilated loops of bowel and if oral contrast is given with the X-ray, there will be no contrast past the obstruction. Think of it as a garden hose that has been kinked and no water is going thru.
In this upper GI- the contrast travels down the small bowel and the entire small bowel is the same caliber. This is normal study with no evidence of obstruction. In a patient with the DS, the patient my have the biliopancreaitc limb obstruction, with an identical X-ray as above, since the oral contrast given will never get to the biliopancreatic limb and it will not show if it is dilated or not.
In duodenal switch operation, a patient may have complete obstruction of the alimentary limb, with nausea, vomiting and abdominal pain, and yet have bowel movements because the content of the biliopancreatic limb is getting to the common channel. Similarly, a patient with biliopancreatic limb may have nausea, but no vomiting, because the obstructed biliopancreatic limb is not connected to the stomach and the content can’t not be expelled from the stomach.
It is critical to make sure that a patient with a suspected bowel obstruction after the DS, is evaluated with the understanding that the common signs and symptoms, and the diagnostic workup will not provide an accurate picture. A patient with the DS or RNY, can have bowel obstruction and still have bowel movement, and no vomiting.
A patient with suspected bowel obstruction should have CT scan of the Abdomen with oral and IV contrast. The cardinal findings will be “dilated loops of bowel with no contrast within the lumen of the bowel”. This is highly suspicious for bowel obstruction after DS, where the regular x ray will not pick this up. Additionally, abnormal liver function test may suggest biliopancreatic limb obstruction.
Bowel Obstruction After Duodenal Switch
August 19, 2014 4:47 pm
One of the potential complications of any abdominal surgery is Bowel Obstruction. If the treating physician (usually the primary care, or the emergency room doctor) is not absolutely clear of the anatomy of a patent post duodenal Switch or the Gastric bypass surgeries this will pose a diagnostic dilemma. In intact anatomy the GI tract start at the mouth and ends up at the rectum as a long tube. After the Duodenal Switch the small bowel has two parallel limbs, the alimentary limb brings the food down from the stomach, and the biliopancreatic limb brings down the biliopancreatic secretions. These two limbs join and form the common channel.
In normal anatomy, bowel obstruction may present with nausea, vomiting, abdominal cramps, inability to pass gas, and/or have bowel movements. In this case, the X-ray will also show dilated loops of bowel and if oral contrast is given with the X-ray, there will be no contrast past the obstruction. Think of it as a garden hose that has been kinked and no water is going thru.
In this upper GI- the contrast travels down the small bowel and the entire small bowel is the same caliber. This is normal study with no evidence of obstruction. In a patient with the DS, the patient my have the biliopancreaitc limb obstruction, with an identical X-ray as above, since the oral contrast given will never get to the biliopancreatic limb and it will not show if it is dilated or not.
In duodenal switch operation, a patient may have complete obstruction of the alimentary limb, with nausea, vomiting and abdominal pain, and yet have bowel movements because the content of the biliopancreatic limb is getting to the common channel. Similarly, a patient with biliopancreatic limb may have nausea, but no vomiting, because the obstructed biliopancreatic limb is not connected to the stomach and the content can’t not be expelled from the stomach.
The images of fluid filled loops of bowel are highly suspicious.
It is critical to make sure that a patient with a suspected bowel obstruction after the DS, is evaluated with the understanding that the common signs and symptoms, and the diagnostic workup will not provide an accurate picture. A patient with the DS or RNY, can have bowel obstruction and still have bowel movement, and no vomiting.
A patient with suspected bowel obstruction should have CT scan of the Abdomen with oral and IV contrast. The cardinal findings will be “dilated loops of bowel with no contrast within the lumen of the bowel”. This is highly suspicious for bowel obstruction after DS, where the regular x ray will not pick this up. Additionally, abnormal liver function test may suggest biliopancreatic limb obstruction.
Patch or Spray Vitamins
August 15, 2014 10:37 pm
At the last group meeting, there were several questions whether vitamin D and other vitamins would be absorbed via patch (transdermal) and spray (buccal/sublingual) routes. After reviewing several resources, the only article I could find was for transdermal Vitamin D absorption. However, if we look at the mechanism for each route we can make an educated assumption.
Transdermal route of absorption (without additional absorption enhancers) (ref) requires a molecular mass less than 500 g/mole, high lipophilicity (affinity to fat or lipids), and low required daily dose (less than 2mg). The fat-soluble vitamins are definitely lipophilic, all of them have molecular weights less than 500 g/mole and daily dose is under 2mg. It seems that hydrophilic medications (that have an affinity to water) may have less ability to be absorbed with this route unless a chemical enhancer is added to the product. Most vitamins and minerals have lower molecular weights except Vitamin B12 which has too high of a molecular weight unless an enhancer is added. The transdermal route has slower absorption than buccal (oral mucosa) but faster than usual tablet oral route. The down side to transdermal route is possible skin issues due to medication, adhesives, and also different rates of absorption due to skin thickness and condition.
Buccal/sublingual route of absorption is dependent on lipid solubility, oil to water partition coeffincient, saliva pH, small to moderate molecular weight, and oral mucosa thickness. The mechanism of action is osmosis, which means items that readily dissolve in water are easily absorbed. Unlike orally ingested medicates, that take time to absorb and need to be filtered and/or processed in the liver, sublingual route is fast absorbing and the liver is bypassed. The down side to this route is it disrupts eating and drinking and is not efficient with smoking due to vasoconstriction.
An e-mail was sent to the companies inquiring about the outcomes of their products with people with malabsorption issues. No response was received from the spray vitamin companies.A request was also sent to obtain any research articles they may have but a response has not been received at this time. The following is the response I received from the maker of Patch MD.
“I am the president and founder of Patch MD. We design Patch MD to help people that have digestive issues and malabsorption. Our whole premise is to avoid the digestive track, by doing so we avoid dealing with conditions such as short bowel syndrome, acid reflux, and bariatric surgery to name a few. People also with Crohn’s disease and iliac disease are challenged with digestion and absorption every day of their life. Our patches are designed specifically to pass nutrition through the skin into the bloodstream. We get letters every day from people that have had bariatric surgery and were unable to get vitamin D, calcium, the B’s and Vitamin A and K, our product works because we use the skin as our delivery system, absorption is through the skin, avoiding all digestive potential issues. The only problem that we may have is we tell our customers to use no lotions or cream in the patch application area, as you may understand it will prevent absorption. We are going to be at a national convention this weekend in Manhattan Beach California to take part and display our products at the ObesityHelp conference. They ask us to take part as they were getting great reviews from their members that are using the patch. All were improving their blood work after taking Patch MD patches.”
Earl Hailey, President Patch MD
In light of the review of data, it would seem that the transdermal route would be beneficial to people who are having issues maintaining blood levels of fat-soluble vitamin levels. The other vitamins also have a good prospect of absorption via transdermal route. Buccal or sublingual (sprays) would seem to have a better outcome for water-soluble vitamins unless there is an additive added to the product to increase the solubility of the fat-soluble vitamins and make them water miscible. We must realize that there is no data for Duodenal Switch patients and very little data regarding these routes of absorption with vitamins specifically. If you are going to try these types of vitamins you should be extremely diligent in following your laboratory studies for vitamin levels with greater frequency until it is determined they are maintaining your blood levels.
Also, it should be noted that water miscible (dry) Vitamin A, D, E, K are the only type of these vitamins a DS patients should be taking. Over the counter Vitamin A, D, E, K are fat-soluble and due to the fat malabsorption after DS these type of vitamins are not appropriate to maintain blood levels. Water miscible (dry) vitamins should NOT be taken with fatty or oily foods and should also be taken 30 minutes prior or 30 minutes after eating. The water miscibility makes them water soluble and therefore will not have optimal absorption if taken with fat. Fat also increases the rate of digestion through the small bowel after DS and decreases the amount of time the vitamin has in the bowel and therefore, decreases absorption. They are best absorbed when taken on their own.
The good news patches and spray routes of administering medications and supplements is an up and coming area of research. There are several ongoing research studies and new developments on the horizon for increasing absorbability of transdermal route with different types of additives and techniques.
Mission Statement
August 14, 2014 1:15 pm
Mission Statement for Central Valley Bariatrics and Dr. Ara Keshishian “The best patient that I can have is the most knowledgeable patient”
This is one of the “lines” that I use during my teaching and consultations sessions. I firmly believe that a patients should have all the pertinent information before they decide to proceed with a treatment plan. Be the treatment is medical in nature or surgical the patient needs to have all the scientific facts before an informed decision is made.
Part of my duty is to provide the information in a scientific and concise fashion in non-medical terms. Additional resources, such as this blog, FB group (The one managed by our office, and those maintained by others) along with the Webinar hosted by us, all serve to complement each other for providing a forum for exchange of information.
The value of information exchanged between patients can not be underestimated. Patients who have walked the path can provide a much more practical experience that I can ever share with a patient. The information shared between patient can and should carry a wider range of topics. It is to be noted however, that no information exchanged between patients should replace the advice of a patients’ surgeon.
For most of us that offer weight loss surgery, we realize that there is a lot more to the care of our patients that just to “cut” and hope for the best! The best outcome is dependent as much on the follow up care as it is to the surgery itself.
I personally believe that the care should be compassionate, respectful, caring and professional. There is no reason why the advice given should include disrespectful, or otherwise demeaning comments, suggestions or innuendoes. These have always been the guiding principals based on which we will conduct our practice on the Facebook, our blog and in person. No one, be patients, my office staff or myself should tolerate any personal threats, foul language or disrespect. For those who may see values to demeaning and inflammatory discussion tones, I wish you the best in other venues.
Ara
August 6, 2014 Group Meeting Recap
August 08, 2014 6:35 pm
August’s group meeting/webinar topic was Vitamin D. Dr. Keshishian will be adding the voice over to the slides and it will be uploaded to when it’s completed. But in the meantime here are some highlights. Webinar here.
Vitamin D is a fat soluble vitamin has many important functions including bone health, cardiovascular health, blood glucose regulation, anti-cancer, anti-inflammatory, muscle function, respirator function, brain development and health, and immune function. There are several very large studies investigating other functions of Vitamin D. Vitamin D knowledge is in the midst of huge changes due to these upcoming studies.
Vitamin D metabolism is a complicated process whether via photo conversion in the skin or supplementation. Either way Vitamin D metabolism requires cholesterol to be converted to its active form. The fat-solubility is the primary reason for deficiency after Doudenal Switch, due to malabsorption of fat needed for conversion of Vitamin D. The Parathyroid gland helps to regulate absorption of Vitamin D. It is an inverse mechanism, meaning a high Parathyroid level signals more absorption of Vitamin D and calcium also.
Vitamin D deficiency is a World Health Organization priority. There are several causes some related to sunscreen use, disease processes, WLS, cola intake, diet related and medications. These can compound Vitamin D deficiencies.
Dr. Keshishian has new guide lines for Vitamin D levels. Due to the changing research regarding Vitamin D these guidelines are changing. There are some endocrinologists in Vitamin D research that are recommending even high standard of Vitamin D. DS patients should be well above the border of insufficient and sufficient due to underlining contributing facts for deficiencies and the lack of absorption. Parathyroid Hormone levels are inversely related. High PTH level can indicate Vitamin D deficiency and increase need for calcium. Calcium blood levels are not a good indicator of calcium or Vitamin D needs as the body is efficient at maintaining Calcium blood levels by breaking down bone mass due to the critic bodies need for circulating calcium.
Supplementation options are as follows: Please note that most over the counter Vitamin D is not appropriate for DS absorption. DS patients need to take “Dry” water miscible Vitamin D3. Please see the previous blog post regarding https://blog.dssurgery.com/2013/08/vitamin-d-and-dry-water-soluble.html for more information and pictures of this type of Vitamin D. Vitamin D is tied to several other nutrients for metabolism such as protein, calcium, magnesium, zinc and potassium. Treatment for correcting iron deficiency and phosphorus intake counter act Vitamin D absorption as do other previous discussed dietary issues. Take oral Vitamin D supplements even if you are receiving injectable Vitamin D.
Be proactive in Vitamin D supplements by monitoring your yearly DS laboratory studies. Please call the office with any questions. If in need of Vitamin D injections please see the previous blog post for related research article and compounding pharmacies. Vitamin D injections are not common place.
Please take the Vitamin D injections post to your treating physician if you are unable to see Dr. Keshishian and are in need of Vitamin D injections. If your treating physician has any questions please let them know Dr. Keshishian is available to answer their questions.
Our food selections for the meeting where all high Vitamin D recipes. Tuna stuff mushroom (Tuna for Vitamin D and mushrooms are a good source of zinc), crustless artichoke and spinach quiche ignore the part of the recipe for the crust and just bake in pie plate without the crust, Panna cotta with a strawberry balsamic compote and toasted flax seed and hemp hulls. The panna cotta is made with milk or almond milk and gelatin which are all important in bone health. Hemp hulls are a protein source as is the milk.
Strawberry Balsamic Compote taken from https://nomnompaleo.com
1/4 C balsamic Vinegar
2C hulled strawberries, thinly sliced
2 TBSP honey
1 TBSP fresh lemon juice
1tsp vanilla extract
1/4 tsp salt
In a sauce pan heat Balsamic vinegar until reduced by half and is a thick syrup. Add the rest of ingredients and simmer over medium heat for 5-10 minutes. Remove pan from heat and use an immersion blender to puree some of the sauce. The texture is to your liking, so puree as much or as little as you would like. Store in a sealed container for up to a week or you can freeze it for long term storage. This site also has a almond milk Panna Cotta but this is not the recipe use at the group meeting.
Panna Cotta Recipe
1/2 C 2% milk mix with 2 1/2 tsp of unflavored gelatin in a bowl to rehydrate the gelatin let sit for 5-10 minutes
In a medium saucepan mix
3 C 2% milk or whole milk
one vanilla bean split in half or 1 tsp vanilla extract
2 TBSP maple syrup
1 tsp salt
heat until steaming but not boiling, about 5-7 minutes. Take off heat.
Mix 1/4C greek style yogurt into the milk and rehydrated gelatin. Then whisk about 1 C of hot milk mixture into the gelatin/milk. Add this mixture into pan of hot milk and whisk well. Pour hot Panna Cotta mixture into ramekins. Refrigerate until set, about 2 hours.
In a small frying pan toast 2 TBSP Flax seed and mix with 2 TBSP hemp hulls. Before serving top with Strawberry Balsamic Compote and flax seed/hemp seed mixture to your taste.
Protein Malnutrition Protein Part 2
July 31, 2014 1:25 pm
Protein energy malnutrition (PEM) or Protein Malnutrition is a problem that can effect a few after weight loss surgery (WLS) and Duodenal Switch (DS). In our previous blog post on protein we discussed the types of essential and non-essential Amino Acids and possible sources. We also discussed how to choose the best bioavailable protein and to vary protein sources to achieve adequate protein levels. There are cases even with adequate protein intake that can result in PEM due to inadequate protein absorption. The early signs of low protein may be low energy, muscle weakness, moodiness, inability to sleep well, joint pain, changes in hair and nails and carb craving. It is imperative after WLS that you maintain your protein levels throughout your lifetime. The minimum protein intake is 80-100 grams per day after WLS. There is no leeway where protein is concerned. It is important in almost ever function in the body.
There are two types of protein energy malnutrition, Kwashiorkor and Marasmus:
Kwashiorkor is a lack of protein intake with adequate or slightly lower caloric intake. It’s symptoms are edema (swelling in legs, ankles, feet) enlarged abdomen, irritability, anorexia, hair discoloration and loss, muscle weakness, changes in psychomotor function, mental lethargy, ulcerations, brittle nails, rash or discoloration of the skin, bradycardia (slow heart rate), non-tender parotid enlargement, enlarged liver with fatty infiltrates that are similar to alcohol liver disease. The edema is caused by osmotic imbalance in the intestinal system causing swelling of the gut. Protein, primarily albumin is responsible for the colloidal pressure within the circulatory and tissue systems. The lack of protein within the circulatory systems cause fluids to “leak” into tissues causing edema. Gastro-intestinal symptoms can include nausea, vomiting, dehydration, diarrhea and increases in appetite. People who have pathological bacteria or parasites and/or after WLS diarrhea can precipitate lower levels of protein. If left untreated can lead to protein malnutrition.
Marasmus is characterized by a lack of protein and caloric intake. The symptoms are an emaciated appearance with edema. There is no liver changes as in Kwashiorkor. This is a starvation mode and can be difficult to treat and can progress to a point of no return.
Catabolysis is the bodies response to lack of protein and or nutrition. This biologic process breaks down muscle and fat to maintain bodily functions. Catabolysis is the body’s last resort to keep it alive. It is a starving body eating itself to keep vital organs alive.
Laboratory Studies are needed to determine the level of malnutrition and treatment routes. These studies include:
- Lipids
- CBC (complete blood count)
- CMP (comprehensive metabolic panel) includes liver and kidney function tests, Calcium and electrolytes
- Albumin Normal is greater than 3.5 gdL (transports nutrients such as calcium, zinc and Vitamin B6)
- Prealbumin (transthyretin) transports retinol (Vitamin A)
- Total protein Normal is greater than 6.3 gdL
- Iron tests such as serum iron, TIBC, and ferritin
- Vitamins and trace minerals such as B12 and folate, vitamin A, vitamin D, vitamin K, B vitamins, calcium, and magnesium
- Ova and Parasite stool testing
Protein is an extremely important nutrient within our bodies and is considered the workhorse in cells and organs. They are responsible for catalysts, messenger duties, structural, immunoprotectors, transporters, buffers, fluid balancers and many other roles. Protein has a hand in synthesizing other proteins, regulates protein turnover, enzyme activity, neurotransmission, gene transcription, transport of other nutrients, messenger and signals for growth hormone and insulin, structure, storage for other nutrients and immunity.
The muscular system is the most obvious structural protein in our bodies, 40% of the total body protein, as is hair, fingernails and cells. Our organs also require protein in order to function appropriately. However, protein’s role in red blood cell formation, size and health is extremely important. If you don’t have adequate protein levels your body can not make red blood cells. Transferrin is a protein that carries iron to receptors. Ferritin is an intercellular protein that stores iron until it is needed. Glycine is a protein for heme synthesis. B12 is also transported via a protein for red blood cell production. Protein is also important in blood clotting and plasma.
Cardiovascular health is also reliant on protein for structure and function. Also, proteins can have a protective effect at the mitochondrial level.
Kidney function relies on protein to regulate the acid base balance and ammonia disposal. The kidneys are also the site of amino acid production.
Protein is also important in bone health as a carrier for Vitamin K and calcium binding, tissue repair, healing and growth. Proteoglycans play a role in extracellular structures such as skin, bone, and cartilage. Also related to the skeletal system are glycoproteins, which also aid in building connective tissue, collagen, elastin and bone matrix.
Central Nervous system relies on proteins for neurotransmission, hormone production and other functions. Protein deficients can lead to neurologic problems such as altered behavior and mental function among other manifestations. The neuorpeptides have actions on transmission functions, mood and behavior. They can also effect a wide range of functions such as blood pressure, body temperature, pain sensation, and learning ability.
Immonoproteins are the group of proteins that provide immune protection such as immunoglobulins and antibodies.
Protein also have storage roles for copper, iron and zinc called metalloproteins. Copper and zinc are considered neurotransmitters, important for iron metabolism, and connective tissue formation in heart, blood vessels and skeletal.
There are situation where your protein needs will increase. In cases of wounds, burns, surgery, stress, sepsis or other illnesses, protein requirements increase. Also age, pregnancy, lactating and increased exercise increases protein needs.
Protein Energy Malnutrition is protein deficit that can and should be avoided after WLS. PEM, if left untreated, can lead to organ failure and death. Protein is crucial in almost every function of the body and without adequate levels there will be symptoms and side effects. Please take care to maintain your protein levels throughout your life. We have discussed several of protein’s function, however, there are many more.
Probiotics, C. diff & Enteric HyperoxaluriaExclusive Member Content
July 26, 2014 3:21 pm
Injectable Vitamin D Information and Research Articles
July 11, 2014 1:06 am
Injectable Vitamin D may be needed in some cases of Vitamin D deficiency or inability to increase Vitamin D level with oral supplements. Vitamin D is a fat soluble vitamin. It plays an important role in bone metabolism and structure. It has also been found to affect the immune regulation, control off- inflammatory reactions, and also be involved in a number of broad cellular functions throughout the body. Until a few years ago, very little attention was given to vitamin D levels. More recently, we have realized that due to a number of factors, there is a tendency for vitamin D deficiency to be present in the U.S. adult population. This finding is even more pronounced and severe in overweight patients.
The recommended dose for vitamin D supplements is much larger today than it was a few years ago. For example, it is not too uncommon to recommend an average dose of a 50,000 (IU) international unit of vitamin D by mouth on a daily basis after the duodenal switch operation.
Since vitamin D is a fat soluble vitamin, it is important that the appropriate type be utilized. Dry formulation of vitamin D is needed to ensure adequate absorption. There are a number of manufacturers that produce these. When searching for Dry Vitamin D the type a patient should be looking for is “Dry” D3-50. Some larger supplement manufacturer’s carry these products. The links to these manufacturers is located here. The “Dry” type of Vitamin D should NOT be taken with fatty or oily foods. Also to optimizes absorption they should be taken either 30 minutes prior to eating food or 30 minutes after eating.
If you are deficient in Vitamin D after trying “Dry” or water miscible Vitamin D then intramuscular Vitamin D injections might be an effective way to normalize your Vitamin D levels. Vitamin D can be formulated and purchased from any compounding pharmacies that are equipped and experienced in the interpretation of injectable vitamins and minerals. Your primary care WILL need to contact the compounding pharmacy of their choose for the recommendations and be willing to make the injections available to you. UNLESS you have been told to stop taking your daily “Dry” Vitamin D tablet supplement you should continue taking it after the injection.
We are supplying the following so that your PCP will understand the research behind injectable Vitamin D and to hopefully ensure that every patient is armed with this knowledge. Vitamin D deficiencies are becoming more common place in society due to the use of sunscreen and sun shielding clothing and hats, not only Duodenal Switch patients.
This is a research paper out of Finland that discusses injectable Vitamin D for the aged. The information can translate to anyone who finds themselves in a Vitamin D deficit state. https://www.gwern.net/docs/nootropics/1992-heikinheimo.pdf
This research paper is out of Australia where despite then sun drenched climate they are experiencing a large amount of people with Vitamin D deficiencies due to sunscreen, veiling, malabsorption, etc.
https://www.direct-ms.org/pdf/VitDGenScience/Vit%20D%20deficiency%20Australia%20art%20and%20ed.pdf
Below find the order sheet with the Injectable Vitamin D concentration listed. The common dosing for the vitamin D is 600,000 IU, deep IM every 6 months till the levels are normalized. The patient then can take the oral supplements only.
Finally, this is an except from an another Australian research paper describing the use of Megadoses of injectable Vitamin D in patients after Biliopancreatic Diversion which has a malabsorptive component similar to Duodenal Switch.
What size is my Bougie?
July 10, 2014 6:57 pm
A Bougie is a flexible plastic tube that comes in different sizes. It can be used to calibrate the size of the stomach during the duodenal switch or Sleeve gastrectomy. It is also used to dilate strictures of the esophagus or the stomach.
I am commonly asked what size is the bougie that I use. My usual answer is that it is equivalent to a 38 or so, and that the size does not matter.
Many surgeons do not use these types dilators, but rather alternative tubes that function as a sizer and a suction tube to eliminates the need for multiple tube insertions and removals.
The July 2014 publication of Obesity Surgery had and article by Spivak et.al. titled “Laparsocopic Sleeve Gastrectomy Using 42-French Versus 32-French Bougie: The First-Year Outcome.” In conclusion they reported that using 42 vs 32 French Bougie does not influence the weight loss of resolution of the combed condition in the first year.
There also other studies that support the position of erring on the side a larger sizer, a 40-French, to decrease the leak rate without having an impact on the excess weight loss at 3 years time.
The take home massage is that the size of the stomach after the sleeve does not predict the outcome of the weight loss surgery independently. There are multiple factors in play such as age, amount of excess weight, diet adherence and exercise.