Older Men With Less Lean Body Mass At Increased Risk of Diabetes

Rita Kalyani, MD

Older men with less lean body mass were more likely to develop diabetes than women, according to new study findings.

Lead author Rita Kalyani, MD, and a team of investigators analyzed nearly 2000 men and women in an effort to assess the relationship of lean body mass with aging to incident diabetes in adults. The findings that lower lean body mass with aging was related to a higher incidence of diabetes in men but not women could lead to new interventions to prevent the development of the chronic condition.

Kalyani, from the Division of Endocrinology, Diabetes & Metabolism at The Johns Hopkins University, collected data from the Baltimore Longitudinal Study of Aging. The population of participants consisted of community dwellers from the Baltimore-Washington, DC, area with above-average educations, income, and access to medical care.

The team included 871 men and 984 women with an average age of 60 years at the initial visit. Participants were eligible if they had >1 dual X-ray absorptiometry (DXA) assessment and did not have diabetes at their initial visit.

DXA was used to determine fat mass, fat-free mass, and bone mineral content for the whole body and lower extremities.

Each participant was monitored overnight, where they fasted for 10 hours and received an oral glucose tolerance test.

Investigators assessed knee extensor strength with the Kin-Com isokinetic and Biodex Multi-Joint System-Pro dynamometers. Strength was measured through concentric quadricep peak torque from the right leg.

The team defined the main outcome, diabetes, as self-reported history and taking glucose-lowering medications; fasting plasma glucose >126 mg/dL and two-hour oral glucose tolerance test glucose >200 mg/dL at the same visit; or fasting plasma glucose >126 mg/dL or two-hour oral glucose tolerance test glucose >200 mg/dL at 2 consecutive visits.

Among the 1855 participants in the study, there were 134 incident cases of diabetes during follow. The median follow-up was 7 years (range 1-15 years) with an average of 3.1 (range 1-14) visits.

A higher quartile of percentage of total lean body mass for men was associated with significantly younger age; lower body mass index, total body weight, and total fat body mass at baseline; lower percentage of participants who developed diabetes during follow-up; lower A1C, fasting glucose, and 2 hour glucose; and lower prediabetes prevalence at baseline (all P <.05).

For both men and women, those in the highest quartile of percentage of total lean body mass had the lowest probability of developing diabetes. Those in the lowest quartile of absolute total lean body mass had the highest probability of developing diabetes, for both men and women.

Men who were in the lowest quartile of knee extensor strength at baseline were at the greatest risk of developing diabetes, while those in the highest had the lowest. And men in the lowest quartile of leg muscle were also at the greatest risk. Such relationships were not observed in women.

For men overall, percentage of total lean body mass (HR, .46; 95% CI, .22-.97), percentage of leg lean mass (HR, .38; 95% CI, .15-.96), and lean to fat mass ratio (HR, .39; 95% CI, .17-.8), were all inversely associated with incident diabetes.

Absolute lean body mass was positively associated with incident diabetes among men and women.

Additional research is needed to assess skeletal muscle mass to learn more about the relationships and sex differences that the study investigators observed.

The study, “The Relationship of Lean Body Mass with Aging to the Development of Diabetes,” was published online in Journal of the Endocrine Society.