Decreased muscle strength is associated with proinflammatory cytokines but not testosterone levels in men with diabetes

Do Strength and Anthropometric Size of the Lower Body Correlate with Serum Testosterone Levels?

PURPOSE

Although lower body strength and size are often regarded as symbols of masculinity, their relationship to testosterone is unclear. This study aimed to determine the correlation between lower body strength, size, and testosterone levels.

MATERIALS AND METHODS

Serum testosterone levels, waist circumference, and body mass index (BMI) were measured in 69 men with erectile dysfunction (age >40 years). The circumferences of the thigh and calf were measured, and the muscle strength of the knee joints was evaluated using an isokinetic dynamometer. Patients were classified into three groups according to testosterone levels (group 1, <230 ng/dL; group 2, 230 to 350 ng/dL; group 3, >350 ng/dL). Differences in calf and thigh circumference, bilateral knee extension, and flexion strength between the three groups were investigated using a one-way analysis of variance. Pearson's chi-square test was used to assess differences in lifestyle habits and underlying diseases. A partial correlation analysis was conducted to determine the association between testosterone levels and lower body size and strength.

RESULTS

There was no difference in BMI among the three groups, but waist circumference was significantly larger in group 1 than in groups 2 and 3. When comparing weight-adjusted values, bilateral thigh circumference showed a significant difference among the three groups. There was also a significant difference between the three groups in the weight-adjusted left calf circumference and in the weight-adjusted right knee extension strength. The partial correlation test showed a significant positive correlation between thigh and calf circumference values adjusted for weight and serum testosterone levels. Weight-adjusted knee extension strength demonstrated a significant positive correlation with serum testosterone levels.

CONCLUSIONS

Weight-adjusted thigh and calf circumferences, along with the thigh-to-waist ratio, showed a positive correlation with testosterone levels. Weight-adjusted knee extension strength was positively correlated with testosterone levels. Therefore, a robust thigh and strong lower body are related to testosterone.

Predictive Models of Muscle Strength in Older People with Type 2 Diabetes Mellitus

Purpose

To propose predictive models for absolute muscle strength (AMS) of elderly people with type 2 Diabetes Mellitus (DM2) in primary health care.

Patients and Methods

The cross-sectional study was conducted with 138 elderly diabetics. The AMS was measured by a JAMAR® hydraulic handgrip dynamometer, determined by the sum of both hands. The following indices were evaluated: waist-to-height ratio (WHtR), body mass index (BMI), Lipid Accumulation Product (LAP), Triglyceride/High Density Lipoprotein (TG/HDL) ratio and platelet/lymphocyte ratio (PLR). Multiple linear regression was used in the statistical analysis.

Results

The final regression model indicated 66.4% (R²=0.66) of the variation in AMS. WHtR decreased AMS by 41.1% (β = -0.19; t = -3.70; p < 0.001), while PLR by 11.3% (β = -0.12; t = -2.36; p = 0.020). Male sex increased AMS by 10.6% (β = 0.32; t = 4.16; p < 0.001), and lean mass (LM) by 0.89% (β = 0.46; t = 6.03; p < 0.001).

Conclusion

WHtR and PLR predicted a decrease, while male sex and LM predicted an increase in AMS. It is suggested that these markers be used as screening measures for variation in AMS in older adults with DM2. These results have relevant practical application in primary health care since the markers are easy to use.

Factors associated with relative muscle strength in patients with type 2 diabetes mellitus

OBJECTIVES

Some patients with type 2 diabetes mellitus (T2DM) experience decreased mobility associated with lower relative muscle strength (normalized with muscle mass). This study aimed to identify factors predicting relative muscle strength of patients with T2DM assessed at regular clinical visits.

METHODS

A total of 144 T2DM patients underwent fasting blood drawing (determining white blood cell count [WBC], diabetic kidney disease [DKD], and glycated hemoglobin [HbA1c]) and the assessment of body composition, diabetic peripheral neuropathy (DPN), activity level, and muscle strength (grip, knee extensor, and ankle plantar flexor strength). One-way ANOVA and multiple regression models were used to identify factors associated with the relative muscle strength.

RESULTS

Our data showed that age, diabetes duration, fat percentage, WBC, DPN, and DKD were negatively associated with the relative muscle strength. Specifically, a greater WBC was associated with lower relative muscle strength of both distal and proximal muscle groups of extremities after the adjustment of other associated factors. DPN was associated with lower relative strength of the distal muscle groups of extremities.

CONCLUSIONS

WBC may be used as a marker of inflammation, and greater count, even within the normal range, is negatively associated with the relative muscle strength in patients with T2DM.