Associations between genetic loci related to lean mass and body composition in type 2 diabetes.

AIM: Several genetic loci related to lean mass have been identified in healthy individuals by genome-wide association studies; however, the contribution of these loci to body composition in type 2 diabetes remains to be investigated. Here, we aimed to clarify the genetic determinants of body composition in individuals with type 2 diabetes. METHODS: A total of 176 Japanese outpatients (70 women and 106 men) with type 2 diabetes were studied using a cross-sectional design. Body composition was measured using bioimpedance analysis with a commercially available device (InBody770). Single-nucleotide polymorphisms in IRS1 (rs2943656), HSD17B11 (rs9991501), VCAN (rs2287926), ADAMTSL3 (rs4842924) and FTO (rs9936385) were evaluated by genotyping. The contributions of single-nucleotide polymorphisms to body composition were examined, considering known clinical determinants. RESULTS: Sex, body composition and age were identified as clinical predictors. IRS1 rs2934656 was identified as an independent predictor of skeletal muscle mass (ß = 0.11, P = 0.026), and ADAMTSL3 rs4842924 was an independent predictor of body fat mass (ß = 0.15, P = 0.0095) and appendicular lean mass (ß = -0.13, P = 0.017). CONCLUSIONS: The findings clarified the contribution of genetic factors - IRS1 and ADAMTSL3 - to interindividual variation in body composition, independent of clinical factors, in type 2 diabetes patients. These data will contribute to the establishment of effective methods for the prediction, prevention, and intervention of sarcopenia and frailty in diabetes patients. Geriatr Gerontol Int 2021; 21: 932-938.

Hyperglycemia in non-obese patients with type 2 diabetes is associated with low muscle mass: The Multicenter Study for Clarifying Evidence for Sarcopenia in Patients with Diabetes Mellitus.

AIMS/INTRODUCTION: Hyperglycemia is a risk factor for sarcopenia when comparing individuals with and without diabetes. However, no studies have investigated whether the findings could be extrapolated to patients with diabetes with relatively higher glycemic levels. Here, we aimed to clarify whether glycemic control was associated with sarcopenia in patients with type 2 diabetes. MATERIALS AND METHODS: Study participants consisted of patients with type 2 diabetes (n = 746, the average age was 69.9 years) and an older general population (n = 2,067, the average age was 68.2 years). Sarcopenia was defined as weak grip strength or slow usual gait speed and low skeletal mass index. RESULTS: Among patients with type 2 diabetes, 52 were diagnosed as having sarcopenia. The frequency of sarcopenia increased linearly with glycated hemoglobin (HbA1c) level, particularly in lean individuals (HbA1c <6.5%, 7.0%, ≥6.5% and <7.0%: 18.5%; HbA1c ≥7.0% and <8.0%: 20.3%; HbA1c ≥8.0%: 26.7%). The linear association was independent of major covariates, including anthropometric factors and duration of diabetes (HbA1c <6.5%: reference; ≥6.5% and <7.0%: odds ratio [OR] 4.38, P = 0.030; HbA1c ≥7.0% and <8.0%: 4.29, P = 0.024; HbA1c ≥8.0%: 7.82, P = 0.003). HbA1c level was specifically associated with low skeletal mass index (HbA1c ≥8.0%: OR 5.42, P < 0.001) rather than weak grip strength (OR 1.89, P = 0.058) or slow gait speed (OR 1.13, P = 0.672). No significant association was observed in the general population with a better glycemic profile. CONCLUSIONS: Poor glycemic control in patients with diabetes was associated with low muscle mass.

Case report: schwannoma arising from the unilateral adrenal area with bilateral hyperaldosteronism.

BACKGROUND: We report a rare case of a juxta-adrenal schwannoma that could not be discriminated from an adrenal tumor before surgical resection and was complicated by bilateral hyperaldosteronism. To the best of our knowledge, this is first case in which both a juxta-adrenal schwannoma and hyperaldosteronism co-existed. CASE PRESENTATION: A 69-year-old male treated for hypertension was found to have a left supra-renal mass (5.8 × 5.2 cm) by abdominal computed tomography. His laboratory data showed that his plasma aldosterone concentration (PAC) was within the normal range, but his plasma renin activity (PRA) was reduced, resulting in an increased aldosterone/renin ratio (ARR). Load tests of captopril or furosemide in the standing position demonstrated autonomous aldosterone secretion and renin suppression. Adrenal venous sampling (AVS) with ACTH stimulation indicated bilateral hypersecretion of aldosterone. A left supra-renal tumor was resected because of the possibility of malignancy and was found to be a benign schwannoma arising from the juxta-adrenal region together with an adrenal gland. The dissected left adrenal gland was morphologically hyperplastic in the zona glomerulosa, but was immunohistochemically negative for CYP11B2 (aldosterone synthase). Multiple CYP11B2-positive adrenocortical micronodules were detected in the adrenal gland, indicating micronodular hyperplasia. Although bilateral aldosteronism was indicated by AVS before the operation, the PRA, PAC and ARR values were within their respective reference ranges after resection of the unilateral tumor, suggesting that the slight increase in hormone secretion from the remaining right-sided lesion could not be detected after resection. CONCLUSION: A clinical and morphologic diagnosis of juxta-adrenal schwannoma is difficult, particularly in a case of hyperaldosteronism, as shown in this case. These data suggest the complexity and difficulty diagnosing adrenal incidentaloma.