Background: 
Sarcopenia is a condition characterized by progressive and generalized loss of skeletal muscle mass and function; and causes serious health-related problems in the elderly with diabetes. Those aged ≥65 years accounts for more than two third of patients with diabetes in Japan today, suggesting that a large fraction of Japanese individuals with diabetes suffer from sarcopenia. However, prevalence of sarcopenia and pre-sarcopenia among the elderly with diabetes in Japan remains unknown.
Aims: The present study is designed to examine prevalence of sarcopenia in elderly Japanese patients with diabetes; and to find possible associations with severity of sarcopenia with dietary intake.
Methods: From 2016 to 2017, we carried out a cross sectional study about 91 type 2 diabetes patients aged 65 and above (47 males and 44 females, mean age 72.7±5.5 years) without overt chronic diabetic complications. In all subjects, grip strength and body composition (SMI; skeletal muscle index, PBF; percent body fat) were measured using the digital hand dynamometer and the bioelectricity impedance measuring device (InBody s10). Based on the diagnostic criteria reported by Chen LK et al (2014), subjects were divided into 4 groups; sarcopenia group (Group S, loss of SMI and grip strength), pre-sarcopenia A group (Group PSa, loss of SMI only), pre-sarcopenia B group (Group PSb, loss of grip strength only), and non-sarcopenia group (Group NS, neither loss of SMI nor grip strength). We evaluated participant characteristics (age, body weight, SMI, PBF), dietary intake, glycemic control (HbA1c), and renal function (Creatinine, BUN, eGFR) among 4 groups.
Results: The prevalence of sarcopenia was 11.0% (Group S, n=10), pre-sarcopenia was 27.0% (Group PSa, n=21; 23.0%, Group PSb, n=4; 4.0%), and the rest was 62.0% (Group NS, n=56). Ages in Group NS was the lowest among the groups. In addition, the body weight and SMI in 2 groups (Group S and PSa) were significantly lower than those in Group NS (p<0.05), and the grip strength was significantly lower in 2 groups (Group S and PSb) than in Group NS (p<0.001, p<0.05, respectively). When compared with the standard values of PBF (male<20%, female<28%), 50.0% in Group S, 81.0% in Group PSa, and 100% in Group PSb exceeded the standard values, indicating that a half of patients with sarcopenia had “sarcopenic obesity”. In the dietary intake survey using standard 3-day food records, no significant difference was observed in total energy and protein intakes among 4 groups. However, the amount of vegetable intakes in Group S was the lowest among the groups, and intakes of micronutrients (vitamin A, vitamin K, Fe) tended to be lower in Group S. Furthermore, the ratios of daily fatty acid intake were 117.4±14.3% for saturated fatty acid (SFA), 100.5±8.2% for monounsaturated fatty acid (MUFA), and 82.0±14.4% for polyunsaturated fatty acid (PUFA) when assuming the quantity of recommendation of Japanese Ministry of Health, Labor and Welfare as 100%. From the results of blood test, there was no significant difference among the 4 groups in HbA1c, creatinine, BUN, and eGFR.
Discussions: The current study found that the prevalence of sarcopenia was approximately 11 %, which is lower than those reported previously presumably. This is presumably because outpatients with relatively preserved activity of daily life were assessed in the current study. We also found that the half of sarcopenia patients found in the current study had obesity, suggesting that so called sarcopenia obesity is critical problem among the Japanese elderly with diabetes. Finally, the current study revealed that those consume more SFA and less PUFA, vitamin A, vitamin K, Fe, and fiber tend to have sarcopenia. These findings might be informative to establish medical nutritional therapies to prevent sarcopenia and sarcopenia obesity among the Japanese elderly with diabetes.

Sarcopenia in Japanese elderly with diabetes: prevalence and characteristics