NEW YORK (Reuters Health) – Insulin sensitizers may reduce the accelerated loss in muscle mass and strength seen in elderly men with type 2 diabetes, according to a report in the September 16th online issue of Diabetes Care.

“These findings require further studies of how insulin sensitizers (particularly metformin) may work to preserve muscle mass,” Dr. Christine G. Lee from Oregon Health and Science University, Portland, Oregon told Reuters Health in an email. “Understanding their mechanism of action on muscle may also lead to the development of more preventive therapies for sarcopenia.”

Dr. Lee and colleagues used data from the Osteoporotic Fractures in Men (MrOS) study to examine longitudinal changes in total and appendicular lean body mass in 3752 older men (65 years and older at baseline) with normoglycemia, impaired fasting glucose (IFG) or diabetes and to determine whether changes differ according to diabetes treatment.

Most men (1853) had normoglycemia, 1403 had IFG, 234 had untreated diabetes, 151 had diabetes treated with insulin sensitizers, and 111 had diabetes treated without insulin sensitizers.

During a mean follow-up of 3.5 years, mean total lean mass decreased in all groups, ranging from a low of 1.4% among men with diabetes treated with insulin sensitizers to 1.7% among normoglycemic men, 1.9% among those with IFG, 2.9% among those with untreated diabetes, and 3.0% among those with diabetes treated with no insulin sensitizers.

Results for appendicular lean mass loss followed the same pattern.

Men with diabetes treated with thiazolidinediones did not differ significantly from normoglycemic men in the amount of total or appendicular lean mass loss, and men with diabetes treated with metformin experienced insignificantly less total and appendicular lean mass loss than did normoglycemic men.

Men with diabetes treated with both metformin and thiazolidinediones experienced significant gains in total and appendicular lean mass compared with normoglycemic men.

Moreover, men treated with metformin or metformin-thiazolidinedione had significantly less total and appendicular lean mass percentage than did men with untreated diabetes or men with diabetes treated without insulin sensitizers.

“These are observational findings, and a clinical trial is needed to validate these findings before considering any changes to the management of older adults with IFG and diabetes,” Dr. Lee said. “At least from our study and others, clinicians should be aware that older adults with diabetes may lose more muscle mass and strength than older adults without diabetes.”

“To understand the clinical relevance of muscle loss, we are currently examining how the percentage change in lean mass is associated with changes in physical performance and muscle strength,” Dr. Lee explained. “We at least know that losing 5% lean mass or greater over 4.6 years is associated with an increased risk of mortality.”

“Perhaps future diabetes studies in older adults should examine the effects of various treatments on functional outcomes and not just focus on macro- or microvascular complications or mortality,” Dr. Lee added.

Reference:

Insulin sensitizers reduce lean mass loss associated with diabetes

Diabetes Care 16 September 2011