Low muscle mass linked to two-fold risk of death from CVD in individuals with diabetes

Researchers have found in a new study that low muscle mass is associated with a two-fold risk of death from heart disease in people with diabetes. Further this association is independent of frailty, glycaemic control and the microvascular complications retinopathy (damage to the blood vessels of the retina) and nephropathy (kidney disease), the analysis of data on US adults found.

The research is  being presented at the Annual Meeting of the European Association for the Study of Diabetes (EASD) in Hamburg, Germany (2-6 Oct).

Sarcopenia – age-related loss of muscle mass and strength – was known to be associated with cardiovascular disease (CVD) and mortality in individuals with diabetes. However, it wasn’t clear to what extent the relationship was being influenced by their blood sugar control or by complications of their diabetes. There was also a lack of consensus on sarcopenia’s impact on cardiovascular disease and mortality in people with diabetes.

To find out more, Dr Jae Myung Yu and Dr Shinje Moon, of Hallym University, Seoul, Republic of South Korea, and colleagues, used data from the National Health and Nutrition Examination Survey (NHANES) on 1,514 adults with diabetes (age >20 years) in the US.

196/1,514 participants (55.6% female) had low muscle mass (ASMI <7 kg/m2 in men or <5.5 kg/m2 in women). The participants with low muscle mass had an average age of 63.5 years and an average diabetes duration of 14.5 years. (No distinction was made between type 1 and type 2 diabetes.)

1,318 participants (48.3% female) had normal muscle mass. Their average age was 54 years and average diabetes duration was 10.4 years.

The NHANES data also included information about a range of other characteristics, including smoking status, alcohol consumption, microvascular complications, HbA1c (a measure of blood sugar control) and frailty.

The participants were followed up for an average of 9.3 years. There were 413 deaths from any cause during this time (106 low muscle mass and 307 normal muscle mass). 147 of these deaths were from CVD (42 low muscle mass, 105 normal muscle mass.)

Low muscle mass was associated with a higher risk of all-cause mortality and CVD mortality. The participants with low muscle mass were 44% more likely to die of any cause during follow-up than those with normal muscle mass. They were also twice as likely to die from CVD as those with normal muscle mass.

The results were adjusted for age, sex, race/ethnicity, smoking status, alcohol consumption, central obesity, history of cancer, hypertension (HTN), dyslipidaemia (unhealthy levels of blood fats), past CVD events including heart attacks, duration of diabetes, microvascular complications and HbA1c.

Further analysis showed that low muscle mass was linked with all-cause mortality and CVD mortality, irrespective of HbA1c and microvascular complications. The association between low muscle mass and all-cause and CVD mortality was also independent of frailty, as defined by a frailty index made up of 46 variables, including memory problems, hospital stays and blood test results.

The study’s authors conclude: “Our results suggest that the increased risk of death in individuals with diabetes who have low muscle mass isn’t mediated or influenced by frailty, poor blood sugar control or microvascular complications but due to the loss of muscle itself. More research is needed to determine just how sarcopenia increases the risk of death.”

Dr Yu adds: “For most people with type 2 diabetes and overweight or obesity, guidelines recommend nutrition, physical activity and behavioural therapies to achieve and maintain weight loss.

“However, there are limitations to assessing treatment goals based on weight loss alone because body weight cannot distinguish between fat and muscle mass and so does not reveal if someone is sarcopenic.

“It is important to consider body composition when treating obesity and managing weight in people with diabetes.”

Reference:

Low muscle mass is associated with a two-fold risk of death from heart disease in people with diabetes, Diabetologia, Meeting: Annual Meeting of the European Association for the Study of Diabetes (EASD).