For Diabetes, Some Need More Exercise

Diabetes risk is greater among South Asians than Europeans

(RxWiki News) To stay fit, people are encouraged to work out at a moderate intensity level several times a week. Even with the same duration of exercise, some might not benefit from this regimen.

Middle-aged people from South Asia were at a greater risk for diabetes compared to white Europeans, a recently published study found.

People from South Asia, which encompasses people from India, Pakistan, Bangladesh, Sri Lanka and Nepal, were overall less active and fit than Europeans.

According to researchers, the findings suggest that people from South Asia may need to work out harder or do higher levels of physical activity to counteract their lower level of fitness compared to Europeans.

"Change up your exercise routine often."

The aim of the study, led by Nazim Ghouri, PhD, honorary clinical lecturer in the Institute of Cardiovascular and Medical Sciences at the University of Glasgow in Scotland, was to see how physical activity and fitness affected insulin resistance and fasting blood sugar levels in South Asian men compared to white European men.

In insulin resistance, the body does not effectively use the insulin that it produces. This causes glucose, or blood sugar, to build up in the blood rather than being absorbed by cells, and can lead to type 2 diabetes.

The study included 100 South Asian participants and 100 European participants who did not have diabetes and were between 40 and 70 years of age.

Participants in the two groups were the same age and had the same body mass index, which is a measure of height and weight.

The researchers measured the amount of glucose in each of the participant's blood. Blood samples were taken after participants fasted.

Participants ran on a treadmill to assess their level of physical fitness and had their height and body mass measured. They also answered a questionnaire on their family health history and smoking status.

The researchers found that the South Asian group had higher blood sugar levels and an increased chance of developing diabetes compared to white men.

A lower level of physical activity accounted for 29 percent of the difference in blood sugar and diabetes risk in South Asians versus Europeans. South Asians engaged in about 32 percent less moderate to vigorous physical activity than Europeans.

Adipose or fat tissue accounted for another 52 percent of the difference between South Asians and Europeans. Having a lower VO2 max (a measure of overall fitness), or the total amount of air that can be inhaled and exhaled, made up about two-thirds of the difference.

South Asians had a 67 percent higher level of insulin resistance than Europeans. The South Asian group also had a 3 percent higher fasting blood sugar level than other group.

"While South Asians spent more years in education, smoked less and drank less alcohol than the Europeans, adjusting for these factors did not change the key study outcomes: difference in VO2 max remained the most important factor associated with South Asians' greater insulin resistance after adjustment for these potential confounders," the researchers wrote in their report.

The lower physical activity levels alone do not explain South Asians' lower fitness levels, according to researchers. 

The authors noted that the participants were not chosen at random and so the findings might not be generalized to other populations.

The study was published online June 28 in the journal Diabetologia, by the European Association for the Study of Diabetes.

The authors do not report any conflicts of interest. The study was supported by the Fellowship from Chest, Heart and Stroke Scotland.

Review Date: 
June 28, 2013