Links found between overweight/obesity, testicular hypotrophy
The study population included 61 male children and adolescents with normal weight, 53 with overweight, and 150 with obesity. Insulin resistance (Homeostatic Model Assessment for Insulin Resistance index ≥ 2.5) was present in 97 participants, 22 had prediabetes, and 3 had type 2 diabetes. Clinical data were collected retrospectively.
Among the boys aged 9-14 years, those with overweight and obesity had significantly lower testicular volume, compared with those of normal weight.
Those who were in Tanner Stage 1 were more likely to have overweight and obesity than those with normal weight, suggesting that “overweight and obese adolescents start puberty later than those of normal weight,” Dr. Cannarella said.
In the 14- to 16-year-old age group, those with insulin resistance had lower testicular volume, compared with those without insulin resistance (HOMA index < 2.5). The number of insulin-resistant adolescents was greater than that of controls in the Tanner stage 2 group.
In both the prepubertal (< 9 years) and pubertal (14-16 years) groups, hyperinsulinemia was associated with lower levels of testicular volume.
Hyperinsulinemia did not influence the timing of puberty onset.
No way to quantify the effect of obesity on fertility just yet
During a press briefing, Dr. Cannarella commented that obesity is likely just one of several factors influencing what appears to be an increase in male infertility over time. “It isn’t of course the only reason, but many factors in our environment have drastically changed, compared to 40 years ago, including the prevalence of heavy metals and endocrine disruptors, and of course, the change in habits and higher prevalence of metabolic disease. All of this has an impact on the proliferation of Sertoli cells in childhood and this may explain the trend toward the decline of sperm concentration and count.”
Longitudinal data are needed to establish cause and effect, she noted. “We need longitudinal studies that link the degrees of testicular volume with the degree of the sperm concentration and count starting from childhood and ending with the adult age. This is the missing link so far.”
Dr. Cannarella has reported no relevant financial relationships. Dr. Herati has reported being an advisor for Dadi, LiNA Medical, and Teleflex.
A version of this article first appeared on Medscape.com.