Examining the association between grip strength and testosterone.

BACKGROUND: Skeletal muscle is an important site for storing proteins and providing general physical function. Recent research has shown that muscle strength decreases earlier than muscle mass decreases, as shown during the aging process. Our article aimed to compare the association between testosterone levels and grip strength to provide an earlier biomarker to detect muscle weakness. METHOD: We adopted quartile-based analysis by dividing handgrip power into quartiles, with all participants in the lowest quartile serving as the reference group. Linear regression analysis was conducted between handgrip power and testosterone. Logistic regression models were used to analyze the longitudinal correlation between testosterone levels and the presence of low muscle strength. RESULTS: Serum testosterone levels had a significant correlation with grip strength in all models (p < .001). In addition, high testosterone levels were negatively associated with low muscle strength in all groups (p < .001). A stronger relationship was observed between testosterone levels and grip strength among non-obese participants than among obese participants. CONCLUSIONS: In conclusion, our study highlighted that testosterone levels are related to greater grip strength.

Mid-arm muscle circumference as a substantial factor against mortality among people with elevated gamma gaps.

Gamma gap is the difference in total serum proteins and albumin and an elevated gamma gap is related to infections, malignancy, and rheumatic diseases. An elevated gamma gap is also associated with higher mortality due to the correlation with inflammatory status. The study aimed to utilize mid-arm muscle circumference (MAMC) to assist in predicting all-cause mortality, cancer mortality, and cardiovascular mortality in people with elevated gamma gaps. Data were obtained from the third U.S. National Health and Nutrition Examination Survey (1988-1994), which contained 14,011 adults aged 20 to 90 years during up to 14.3 years of follow-up. The Primary analysis examined MAMC in tertiles and revealed the demographic and characteristics of the study population. Receiver operating characteristic curve analysis was used and the most suitable cut-off point of gamma gap was 3.65 g/dl. The secondary analysis employed Cox proportional hazards models stratified by age, gender and body mass index to evaluate the hazard ratios for all-cause mortality, cancer mortality, and cardiovascular mortality associated with the MAMC. As the MAMC tertiles increased in group with gamma gap ≥ 3.65 g/dl, individuals with elder age (60-90 years), normal range of body mass index (19-24.9 kg/m2), and male gender tended to have lower hazard ratios for all-cause mortality, cancer mortality, and cardiovascular mortality. These substantial findings indicate that higher MAMC may be a protective factor of all cause-mortality, cancer mortality, and cardiovascular mortality among older male with normal body mass index and elevated gamma gaps.

Mid-arm muscle circumference as a surrogate in predicting insulin resistance in non-obese elderly individuals.

The homeostatic model assessment of insulin resistance (HOMA-IR) was used to measure the degree of insulin resistance (IR). Previous literature revealed that mid-arm muscle circumference (MAMC) is one of the anthropometric indicators for nutritional status and the relationship between MAMC and HOMA-IR remains uncertain in the obese and non-obese elderly individuals. The present study included 5,607 participants aged between 60 to 84 years old, using data from the 1999 to 2006 National Health and Nutrition Examination Survey (NHANES). To further explore the association between HOMA-IR and MAMC in the obese and non-obese elderly population using multivariate Cox regression analyses, we divided the participants into obese (BMI ≥ 30 kg/m2) group and non-obese (19 ≤ BMI < 30 kg/m2) group in this study; each group was then divided into quartiles based on their MAMC levels. A positive association was noted between the MAMC and HOMA-IR in all of the designed models initially. After adjusting for multiple covariates, a higher level of the MAMC was significantly associated with elevated HOMA-IR (P < 0.05) in the non-obesity group, which was not the case in the obesity group. Additionally, subjects in the higher quartiles of MAMC tended to have higher HOMA-IR with a significant association (P for trend = 0.003 in model 1; P for trend < 0.001 in model 2, 3, and 4). These results demonstrated that the MAMC can be an auxiliary indicator of HOMA-IR in non-obese elderly individuals and may have substantial additional value in screening for IR if well extrapolated.

Does Serum Homocysteine Explain the Connection Between Sexual Frequency and Cardiovascular Risk?

BACKGROUND: Sexual activity correlates with various health issues, and homocysteine is considered an independent risk factor for cardiovascular events and atherosclerosis. Research on the relation of sexual activity to sexual frequency and homocysteine is sparse. AIM: To examine the association between sexual frequency and homocysteine in the general population in the United States. METHODS: In total, 2,267 eligible participants 20 to 59 years old who had serum homocysteine data and completed a sexual behavior questionnaire were enrolled from the National Health and Nutrition Examination Survey of 2005 to 2006. The correlation between sexual frequency and serum homocysteine levels was analyzed using a linear regression model and an extended-model approach was performed for covariate adjustment. OUTCOMES: Individuals, especially men, in the lower quartiles of sexual frequency had significantly higher serum homocysteine levels, and a sex difference was identified in subgroup analysis. RESULTS: In a model of quartile-based analysis after adjustment for age, sex, and race and ethnicity, the regression coefficient of the highest quartile of sexual frequency compared with the lowest quartile was -1.326 (P = .012). After further adjustment for multiple covariates, the inverse association between sexual frequency and serum homocysteine levels remained unchanged. Negative trends maintained statistical significance (P for trend < .05). In subgroup analysis by sex, a negative association between sexual frequency and serum homocysteine levels remained unchanged in men even after adjusting for multiple covariates, but not in women. CLINICAL IMPLICATIONS: Clinical physicians in primary care should support patients' sexual activity, and there are implications for health promotion programs. STRENGTHS AND LIMITATIONS: This is the first observational investigation stratified by sex to evaluate the correlation between sexual frequency and serum homocysteine levels. The study was a cross-sectional observational investigation and the causal relation should be evaluated in a follow-up study. CONCLUSION: Decreased sexual frequency correlated with higher homocysteine levels in a nationally representative sample of US adults, especially men; this might increase the risk of cardiovascular disease or other atherothrombotic events. Yang H-F, Kao T-W, Lin Y-Y, et al. Does Serum Homocysteine Explain the Connection Between Sexual Frequency and Cardiovascular Risk? J Sex Med 2017;14:910-917.

The Risk of Nephrolithiasis Among Patients With Ankylosing Spondylitis: a Population-Based Cohort Study.

OBJECTIVES: This study aims to investigate the correlation of ankylosing spondylitis (AS) with nephrolithiasis by performing a nationwide population- based cohort study. PATIENTS AND METHODS: The data used in this retrospective cohort study were collected from the Taiwan National Health Insurance Research database. The study included a total of 3,334 AS patients (1,914 males, 1,420 females; mean age 44.51±16.83 years; range 22 to 79 years) and 13,336 non-AS patients (7,656 males, 5,680 females; mean age 44.27±17.01 years; range 21 to 78 years) who had been followed-up on an average of 6.78 years and 6.75 years, respectively, between January 2000 and December 2008. RESULTS: The percentage of newly diagnosed nephrolithiasis was 4.8% in all study subjects. However, the percentages of newly diagnosed nephrolithiasis were 5.76% and 4.58% in the AS and non-AS cohorts, respectively. After adjusting the patients' sex, age, urbanization level, and comorbidities, the hazard ratio obtained from our multivariable Cox model was 1.19. CONCLUSION: Our study findings indicate that patients with AS are more likely to develop nephrolithiasis than non-AS patients.