Diabetes & Cardiovascular Disease Risk Factors among South Asians Compared to other Ethnic Groups

Dr. Alka Kanaya talked about Diabetes and cardiovascular disease risk factors in multi-ethnic groups comparison studies, at a joint event hosted by  www.eppicglobal.org and  www.bio2devicegroup.org .  Dr. Kanaya is Professor of Medicine, Epidemiology, and Biostatistics at UCSF and a principal investigator in Mediators of Atherosclerosis in South Asians Living in America or MASALA study, for short.  Primary objective of the study was to research and understand the high incidence of diabetes and CHD among people of South Asian origin.

Kanaya first shared information on South Asians (will be referred here as SA) and then discussed the study results in the context of multi ethnic comparison.  Currently there are 3.4 M people from South Asia living in the US.  It is the second fastest growing racial/ ethnic minority in the US.  They constitute 20% of all Asians and 75% of them are foreign born.  Although there is little organized medical data on SAs, overall they have relatively lower body weight (BMI), have more central abdominal obesity, and experience higher rates of diabetes and indicate high risk of early heart disease.

MASALA study began in March, 2010 and constitutes a total sample of 906 people, between the ages of 40 and 84.  People with prior history of any cardiovascular disease, those in active cancer treatments, those planning to move out of the area in the next 5 years, and nursing home residents, were excluded.  Data collected included weight, height, waist, seated BP, Ankle-brachial index (ABI predicts the sevearity of PAD, peripheral artery disease), 2 hour OGTT (oral glucose tolerance test), abdominal CT, and several blood tests and extremely detailed questionnaires regarding family history and information about personal habits like alcohol, smoking, sleep, diet and exercise.

Results from MASALA study were compared to results on almost all similar measures with Whites, Latinos, African-Americans and Chinese populations in ongoing MESA study.  See the websites of MESA (www.mesa.nhlbi.org) and MASALA (www.masalastudy.org) studies to see many interesting details on several patterns that emerged.  Kanaya specifically discussed some patterns among South Asians when compared with other ethnic groups.

When adjusted by sex and age, South Asians had significantly high rates of hypertension.  However, there weren’t major or alarming differences in cholesterol.  One of the reasons could be that South Asians were overall more educated, from higher socio-economic background, and were more likely to be using statins and other cholesterol lowering drugs

Most alarming differences were observed in diabetes and pre-diabetes levels.  Almost 30% of men and almost 15% of South Asian women had Diabetes Mellitus, versus 20% or lower among other groups of men, and 13% or lower among other groups of women.  Nearly 37% of SA men and 29% of SA women had IFG (impaired fasting glucose indicative of pre-diabetes), compared to 20% or less for men and 13% or less for women from other groups.  When adjusted for many indicators including age, sex, cholesterol, triglycerides, hypertension etc., South Asians were significantly more likely to have type 2 diabetes.

When adjusted for age, sex, BMI, and waist and excluding those on diabetes meds, this high incidence of Diabetes Mellitus among South Asians seemed to be associated with higher levels of insulin resistance, lower pancreatic B-cell function, and (as confirmed by abdominal CT data) high amount of body fat around abdominal regions and in the liver.

Mercat de la Boqueria, fruits & vegetables (Photo credit: Wikipedia)

Among lifestyle factors, the high rates of DM (Diabetes Mellitus) among SA was attributed to poor diet with less fruits and vegetables and more Western diet (including pizza, pasta etc.), sweets, refined grains, and consumption of high animal based protein in the diet and low levels of exercise.  Considering that even on a relatively leaner body, South Asians carry more fat, the study concluded that guidelines for BMI should be lower for people of South Asian origin.

The study concluded that 75% of South Asians were overweight or obese using the recommended BMI cut-points in Asians.  Compared to other racial/ ethnic groups, South Asians were from higher socio economic status, had low smoking rates, and low to moderate alcohol use.  They also indicated very low physical activity, higher diabetes prevalence (specially among men), second highest prevalence of high blood pressure, and men have more coronary calcium than other groups.

A yoga class. (Photo credit: Wikipedia)

Some of the recommendations for South Asians from the study were, to know the risk factors, work towards ideal BMI goal (less than 23 kg/m2 for SA), remember waist size matters more than BMI, walk at least 30 minutes a day 5 days a week, avoid a diet high in animal protein and refined carbs, and then something interesting – do Yoga!

Kanaya also shared results from her PRYSMS study that assigned subjects with metabolic syndrome into two groups, one practicing Restorative Yoga (included lot of lying down and relaxing poses) and other, Stretching Exercises.  In 6 months, both groups improved their PA and calorie intake.  Favorable changes in the stretching group included, lowered triglycerides and improved mental health.  Restorative yoga group reduced and sustained weight loss and weight girth loss but not visceral fat area.  Finally, only yoga group indicated reduction of fasting glucose and overall favorable metabolic changes in the yoga group included lowering of fasting insulin, glucose, HbA1c and HDL.

One wonders if very determined focus on material wealth goes with more stress.  In any case, it shows once again that stress relief is a key for improved health.  This was a fascinating talk and was followed by Q&A and animated discussion.