Muscle mass checks diabetes

In a study conducted by the city-based St John’s Research Institute (SJRI) published in the European Journal of Clinical Nutrition, researchers indicate that the propensity for diabetes is heightened not merely by obesity, but by weak muscle mass as well. A regular exercise regimen and a diet with adequate high-quality proteins might serve to delay diabetes even in those genetically at risk, the study suggests.

The SJRI study correlated muscle mass and strength in lean Indian men, and pointed to evidence that weak muscles lead to low disposal of glucose, and also loss of sensitivity to insulin, a hormone produced by the pancreas. Increasing glucose levels causes diabetes, irrespective of body weight.

SJRI dean, Anura V Kurpad, said, “With more and more young Indians working in sedentary jobs and leading a lifestyle that does not involve a great deal of physical exertion, there are now commonly-used phrases about India being the ‘diabetic capital of the world’. We conducted the study to examine the reasons for this heightened risk of diabetes.”

The paper was authored by Kurpad and fellow-researchers Uma S Unni, G Ramakrishnan, T Raj, RP Kishore, T Thomas, and M Vaz. The researchers used an “insulin clamp” technique to determine the body’s sensitivity or resistance to insulin, a hormone produced in the pancreas. Type 2 diabetes is caused by the body’s low production of, or resistance, to insulin.

Explaining the method used, Kurpad said, “We injected glucose and insulin in carefully calculated quantities to maintain (or clamp) the glucose at a constant level. With these infusion rates, we could mathematically work out how insulin-sensitive the body is.”

The study, first initiated in late 2006, assessed the association of body fat, muscle and muscle function with insulin sensitivity in young, healthy, non-obese Indian men with a normal body mass index (BMI), ranging from 15 to 25 kg/m2. It found that though fatness was related to diabetes, as has already been proven, muscle strength and muscle function too was related to the onset of diabetes.

The study demonstrated that even among those with a low or normal BMI, those with a low BMI are more insulin-sensitive than those with a relatively higher BMI, even if they are in the normal BMI range.

“The test conducted on subjects for the purpose of the research involved ‘grip strength’ as well as fatigue in maintaining that grip. Grip was tested by getting the subject to press down an object—and the fatigue thus caused was measured too. Exercise improves muscle function and insulin-sensitivity through defined biochemical mechanisms in the muscles,” said Kurpad, adding that early signs of insulin-resistance are linked to muscle strength. 

Cricket once a week not enough
The study conducted by the city-based St John’s Research Institute (SJRI) was inspired by the observation that despite low nutrition intake, labourers perform strenuous tasks as they have a strongly-built muscular system; there is also concern for the sedentary lifestyle of the modern Indian professional: “This study is aimed at India’s youth; we don’t see young professionals today playing group games like football or engaging in physical activity. While still students, there are many who play games.

At work, however, the demands and schedules do not allow time for games. If they play at all, it is usually cricket, about once a week—that doesn’t quite count as strenuous exercise,” Kurpad explained.

The findings of the research study indicate that even if there is a genetic predisposition to diabetes, its onset might be delayed among those who maintain an active lifestyle. However, the findings are yet to be tried on the field.

‘Diabetic capital of the world’
Diabetic patients in India have more than doubled — from 19 million in 1995 to 42 million now. The rate of increase has caused India to be termed the ‘diabetic capital of the world’.

The Diabetes Atlas, a global monitor, predicts that over 69 million people are likely to be affected by the disorder in the country by 2025.

Diabetes, the fourth-largest cause of death, already affects 11 per cent of the country’s urban population and three per cent of its rural population above the age of 15.