Traditional signs and symptoms commonly attributed to hypogonadism do not correlate with testosterone levels: the Cooper Center Longitudinal Study Experience.

Evidence suggests that substantial testosterone therapy is occurring without checking levels of testosterone, presumably based on the presence of symptoms alone. We sought to explore the relationship between total testosterone level and non-specific symptoms, metabolic abnormalities, and sexual dysfunction associated with hypogonadism. This cross-sectional study included 2994 generally healthy men aged 50-79 years examined at a preventive medicine clinic in Dallas, TX from January 2012 to March 2016. Symptoms of hypogonadism were assessed. Screening morning total testosterone levels were measured and categorized into low (<250 ng/dL), low normal (250-399 ng/dL), and normal (≥400 ng/dL). Multiple logistic regression models were used to test the associations between total testosterone and signs and symptoms of hypogonadism. When considering symptoms and signs of hypogonadism, only decreased libido (OR 1.31, 95% CI 1.00 to 1.70), fasting glucose ≥100 mg/dL (OR 1.47, CI 1.15 to 1.88), and hemoglobin A1c over 6% (OR 1.47, 95% CI 1.06 to 2.03) were associated with increased odds of low testosterone after adjustment for age, body mass index, and cardiorespiratory fitness. Testosterone levels were not associated with fatigue, depression, or erectile dysfunction in our study (p>0.6). In this preventive medicine cohort, symptoms commonly attributed to testosterone deficiency were not associated with low total testosterone levels.

The association of cardiorespiratory fitness, body mass index, and age with testosterone levels at screening of healthy men undergoing preventive medical examinations: The Cooper Center Longitudinal Study.

BACKGROUND: Currently, exogenous hormone replacement is used in many men with hypogonadism without clear organic cause. This study examines the contribution of modifiable health behaviors, i.e., physical activity and weight control, to the maintenance of testosterone levels with aging. METHODS: In a cross-sectional study of 2994 healthy men aged 50-79 years examined at a preventive medicine clinic from January 2012 to March 2016, screening morning total testosterone levels were measured and categorized as low (<250 ng/dL), low normal (250-399 ng/dL), and normal (>400 ng/dL). Cardiorespiratory fitness (fitness) was estimated from a maximal exercise treadmill test. Multiple logistic regression models were used to test the associations between low testosterone levels and age, body mass index (BMI), and fitness. FINDINGS: Mean testosterone levels were in the normal range for each age group (50-59, 60-69, and 70-79). There was a similar prevalence of low testosterone in each age group (11·3%, 10%, and 10·5%, respectively). The prevalence of low testosterone was positively associated with BMI and negatively associated with fitness but was not associated with age. INTERPRETATION: This study found no evidence that low testosterone is an inevitable consequence of aging. Maintenance of healthy weight and fitness may help maintain normal testosterone levels.

Association between omega-3 fatty acids and serum prostate-specific antigen.

We examined the association between omega-3 fatty acids (O3FAs) and prostate-specific antigen (PSA) in a cross-sectional analysis of 6219 men examined at the Cooper Clinic from 2009 to 2013. We assayed O3FAs from red blood cell membranes and measured PSA levels in study participants. Multiple logistic regression was used to examine the association between O3FAs and PSA. The mean age of study participants was 55.5 years (SD = 9.8) with a mean PSA level of 1.31 ng/mL (SD = 1.5). Unadjusted analyses indicated that there was a slight, direct association with PSA and each of the O3FAs tested. However, after adjusting for age and body mass index (BMI), the associations were reversed but nonsignificant [odds ratio (OR) for PSA > 4 ng/mL: total omega-3 OR = 0.98 per each 1% of total fatty acids, 95% confidence interval (CI) = 0.93-1.03; docosahexaenoic acid OR = 1.01, 95% CI = 0.92-1.11; omega-3 index OR = 0.99, 95% CI = 0.93-1.05). Similar results were obtained after age and BMI adjustment when the omega-3 index was divided into undesirable (0.01-3.99%), intermediate (4.0-7.99%), and desirable ranges ( ≥ 8.0%). Given that the study had >80% power to detect an odds ratio <0.9 or >1.1, we conclude that associations between O3FAs and PSA levels are either nonexistent or quite weak in the population that this healthy sample represents.