1.
Serum Vitamin D Affected Type 2 Diabetes though Altering Lipid Profile and Modified the Effects of Testosterone on Diabetes Status.
Wang, L, Liu, X, Hou, J, Wei, D, Liu, P, Fan, K, Zhang, L, Nie, L, Li, X, Huo, W, et al
Nutrients. 2020;(1)
Abstract
Numerous studies have investigated the associations between serum vitamin D or testosterone and diabetes; however, inconsistencies are observed. Whether there is an interaction between vitamin D and testosterone and whether the lipid profile (total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C)) mediates the association between vitamin D and diabetes is unclear. To investigate the effect of vitamin D and testosterone on impaired fasting glucose (IFG) or type 2 diabetes mellitus (T2DM), 2659 participants from the Henan Rural Cohort were included in the case-control study. Generalized linear models were utilized to estimate associations of vitamin D with IFG or T2DM and interactive effects of vitamin D and testosterone on IFG or T2DM. Principal component analysis (PCA) and mediation analysis were used to estimate whether the lipid profile mediated the association of vitamin D with IFG or T2DM. Serum 25(OH)D3, 25(OH)D2, and total 25(OH)D levels were negatively correlated with IFG (odds ratios (ORs) (95% confidence intervals (CIs)): 0.99 (0.97, 1.00), 0.85 (0.82, 0.88), and 0.97 (0.96, 0.98), respectively). Similarity results for associations between serum 25(OH)D2 and total 25(OH)D with T2DM (ORs (95%CIs): 0.84 (0.81, 0.88) and 0.97 (0.96, 0.99)) were observed, whereas serum 25(OH)D3 was negatively correlated to T2DM only in the quartile 2 (Q2) and Q3 groups (both p < 0.05). The lipid profile, mainly TC and TG, partly mediated the relationship between 25(OH)D2 or total 25(OH)D and IFG or T2DM and the proportion explained was from 2.74 to 17.46%. Furthermore, interactive effects of serum 25(OH)D2, total 25(OH)D, and testosterone on T2DM were observed in females (both p for interactive <0.05), implying that the positive association between serum testosterone and T2DM was vanished when 25(OH)D2 was higher than 10.04 ng/mL or total 25(OH)D was higher than 40.04 ng/mL. Therefore, ensuring adequate vitamin D levels could reduce the prevalence of IFG and T2DM, especially in females with high levels of testosterone.
2.
Effects of testosterone supplement treatment in hypogonadal adult males with T2DM: a meta-analysis and systematic review.
Zhang, J, Yang, B, Xiao, W, Li, X, Li, H
World journal of urology. 2018;(8):1315-1326
Abstract
PURPOSE Testosterone supplement treatment (TST) is a classic therapy for hypogonadal men with type 2 diabetes mellitus (T2DM), but the effects of TST in different studies are inconsistent. We conducted this meta-analysis to evaluate the precise role of TST in hypogonadal men with T2DM. METHODS PubMed, Embase, Cochrane Library and Web of Science were searched to identify qualified randomized controlled trials (RCTs). Pooled mean differences (MDs) with 95% confidence intervals (CIs) were calculated to measure the specific effects of TST. Trial sequential analysis was performed to verify the pooled results. RESULTS A total of eight RCTs were enrolled in our meta-analysis, including 596 hypogonadal participants with T2DM. Compared with comparators, TST can significantly improve glycemic control by reducing homeostatic model assessment of insulin resistance (MD - 0.79, 95% CI - 1.23 to - 0.34), fasting glucose (MD - 0.98, 95% CI - 1.13 to - 0.54), fasting insulin (MD - 2.47, 95% CI - 3.99 to - 0.95) and HbA1c% (MD - 0.45, 95% CI - 0.73 to - 0.16). In addition, TST can result in a decline in cholesterol (MD - 0.29, 95% CI - 0.38 to - 0.19) and triglyceride (MD - 0.37, 95% CI - 0.59 to - 0.15). CONCLUSION Our results indicated that TST can improve glycemic control and decrease TC and TG in hypogonadal patients with T2DM. We recommend TST during the anti-diabetic therapy in these patients.