Muscle strength, an independent determinant of glycemic control in older adults with long-standing type 2 diabetes: a prospective cohort study

Background Although the proportion of older patients with type 2 diabetes mellitus (T2DM) has increased, few studies have reported the factors affecting glucose levels in older patients with long-standing T2DM. This study assessed the determinants of glycemic control in older adults with T2DM of a duration of >= 10 years, including muscle mass, muscle quality, and beta-cell function. Methods This was a prospective study of older patients aged >= 60 years with a T2DM duration of >= 10 years. The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) index, handgrip strength (HGS), and body composition through bioelectrical impedance analysis were assessed. The primary outcome was a composite of: (i) increment of glycated hemoglobin (HbA1c) from the baseline >= 0.6% and (ii) HbA1c >= 9% at any time point during the follow-up period. To find the predicting determinants of the outcome, we performed the Cox proportional hazard analysis. Results Among 100 patients (mean age, 64.0 +/- 8.6 years; median duration of diabetes, 20 [interquartile range (IQR), 17-23] years; median HbA1c at baseline, 7.1 [IQR, 6.7-7.4] %), the primary outcome was observed in 40 (40.0%) patients during 4.0 (IQR 2.3-5.0) years of follow-up. A Cox proportional hazards model adjusted for age, sex, baseline HbA1c, obesity, duration of DM and anti-diabetic medication at baseline showed that low HGS and insulin resistance at the baseline were independent determinants of the primary outcome (hazard ratio [HR] = 2.23 [95% confidence interval (CI), 1.06-4.72] and 2.39 [95% CI, 1.18-4.83], respectively). Sex stratification confirmed that HGS and muscle mass were independent determinants of the primary outcome only in women (HR per quartile, 0.58 [95% CI, 0.37-0.93] and 0.46 [95% CI, 0.25-0.85], respectively). `. Conclusions Low HGS and insulin resistance were independent risk factors for aggravated glycemic control among older patients with long standing T2DM.

Automated summary

In older patients with long-standing T2DM, low handgrip strength and insulin resistance were identified as independent risk factors for aggravated glycemic control. These findings emphasize the importance of muscle strength and insulin sensitivity in managing diabetes in older adults.