Obesity, type 2 diabetes, and testosterone in ageing men

Abstract

In the absence of obesity, adverse lifestyle behaviours, and use of medication such as opioids serum testosterone concentrations decrease by only a minimal amount at least until very advanced age in most men. Obesity is heterogeneous in its phenotype, and it is the accumulation of excess adipose tissue viscerally associated with insulin resistance, dyslipidaemia, inflammation, hypothalamic leptin resistance and gliosis that underpins the functional hypogonadism of obesity. Both central (hypothalamic) and peripheral mechanisms are involved resulting in a low serum total testosterone concentration, while LH and FSH are typically in the normal range. Peripherally a decrease in serum sex hormone binding globulin (SHBG) concentration only partially explains the decrease in testosterone and there is increasing evidence for direct effects in the testis. Men with obesity associated functional hypogonadism and serum testosterone concentrations below 16 nmol/L are at increased risk of incident type 2 diabetes (T2D); high testosterone concentrations are protective. The magnitude of weight loss is linearly associated with an increase in serum testosterone concentration and with the likelihood of preventing T2D or reverting newly diagnosed disease; treatment with testosterone for 2 years increases the probability of a positive outcome from a lifestyle intervention alone by approximately 40%. Whether the additional favourable benefits of testosterone treatment on muscle mass and strength and bone density and quality in the long-term remains to be determined.

Higher Serum Testosterone Level Was Associated with a Lower Risk of Prediabetes in US Adults: Findings from Nationally Representative Data

“…The findings are consistent with some existing studies that have assessed the association between testosterone levels and diabetes [ 7 , 8 , 9 ]. Several systematic reviews and meta-analyses on the association between testosterone levels and diabetes have been published [ 7 , 8 , 9 , 24 ]. In a meta-analysis of cross-sectional studies, the women with diabetes had significantly higher levels of testosterone than those without diabetes (mean difference, 6.1 ng/dL) [ 8 ].…”

“…There are several consequences of circadian disruption, including sleep disorders, metabolic syndrome, and obesity. These conditions have been shown to be related to both low testosterone and a high risk of diabetes [ 24 ]. It is worth mentioning that plasma testosterone levels vary in a circadian manner: the highest upon waking and decreasing to a low point at the end of the day [ 30 ].…”

Pharmacotherapy of male hypogonadism

“…In all the meta-analyses, TRT exerts a similar, positive effect in reducing fat mass and in increasing muscle mass, without changing body mass index (BMI) or weight [37,43,44]. A positive effect on fasting glycemia was also apparent, whereas a reduction in total cholesterol and triglycerides were evident in some, but not all, the meta-analyses [37].…”

Correlations of adaptive potential with metabolic factors in workers of the Yakutia river fleet

“…У мужчин с низким уровнем тестостерона в сыворотке, обусловленным ожирением, существует линейно-обратная связь между снижением веса и увеличением концентрации тестостерона в сыворотке. Низкие концентрации тестостерона в сыворотке с возрастом в основном являются следствием хронических заболеваний, связанных с ожирением, употребления опиоидов и модифицируемого поведения, связанного со здоровьем [22].…”