To investigate the metabolic characteristics, body composition and dietary intake in elderly sarcopenia patients with type 2 diabetes(T2DM).

A total of 652 T2DM patients(327 males and 325 females)aged over 60 years were selected from endocrinology department of nine different hospitals in Beijing.Body composition was measured by bioimpedance analysis, and the appendicular skeletal mass index(ASMI)was calculated.Sarcopenia was defined as body height-adjusted skeletal muscle mass(ASMI)below the lower quintile of the young reference group.The diagnostic cutoff points for sarcopenia were 7.18 kg/m² for men and 5.73 kg/m² for women.All patients were divided into the sarcopenia group versus the control group(below vs.not below 7.18 kg/m² for men and 5.73 kg/m² for women). The anthropometric parameters, body composition, biochemical laboratory results and dietary intake were compared between the two groups.The blood glucose target levels were less than 7 mmol/L of fasting plasma glucose(FPG)or less than 7% of haemoglobin A1c(HbA1c). The obesity ratio was calculated according to body fat percentage more than 25% in men and more than 30% in women as obesity.

There were 116(17.8%)patients in the sarcopenia group(men/women, 82/34), and 536(82.2%)patients in the control group(men/women, 245/291). Age was higher in the sarcopenia group than in the control group(t=4.385, P=0.000), and body mass index and waist hip ratio(WHR)were lower in the sarcopenia group than in the control group(t=11.724 and 4.173, P=0.000 and 0.000). FPG[(7.5±2.4)mmol/L vs.(8.5±2.5)mmol/L, t=-3.450, P=0.001]and HbA1c[(7.0±1.6)% vs.(8.2±1.7)%, t=-5.745, P=0.000]were higher in male sarcopenia group than in male control group.The control rate of FPG(127.0% or 51.8% vs.27.0% or 32.9%, χ²=8.817, P=0.003)and HbA1c(131.0% or 53.5% vs.23.0% or 28.0%, χ²=15.934, P=0.000)were lower in the sarcopenia group than in the control group.The red blood cell counts, hemoglobin and serum albumin levels, estimated glomerular filtration rate(eGFR)were lower in male sarcopenia group than in the male control group(P<0.05). eGFR was lower in female sarcopenia group than in female control group(t=4.090, P=0.000). Both in men and women, ASMI, grip power, fatless circumference on upper arm, bone mineral content and basal metabolic rate were lower in the sarcopenia group than in the control group(P<0.05). The total daily intake of energy, carbohydrate, protein and fat were lower in male sarcopenia group than in male control group(P<0.05).

Compared with the control group, sarcopenia patients are older with worse glycemic control and lower levels of BMI, WHR, renal function, muscle mass and muscle strength.Sarcopenia patients are more prone to osteoporosis.Furthermore, they have poorer nutritional status with an imbalance of dietary intake.Appropriate increase of protein especially high quality protein intake should be recommended to sarcopenia patients with T2DM.

Diabetes mellitus; Sarcopenia; Nutrition assessment; Metabolism