August 8th, 2022

Diet, obesity and insulin resistance are associated with smaller testicles in males

Rossella Cannarella presented data on the impact of obesity, hyperinsulinemia, insulin resistance and type 2 diabetes in a cohort of boys aged 16 years and younger on the testicles of male teens in Italy. Testicular volume, age, BMI, insulin, fasting glycemia, HbA1c and glucose levels at 120 minutes after an oral glucose tolerance test were all measured and reported.

The study cohort included 61 adolescents with normal weight, 53 with overweight and 150 with obesity.

There were 45 participants with insulin levels of 20 IU/mL or higher, and 97 were considered insulin resistant with a homeostasis model of assessment of insulin resistance of 2.5 or greater. Prediabetes was prevalent in 22 boys, and three had type 2 diabetes.

• In the peripubertal age group, testicular volume was higher in those with normal weight compared with overweight or obesity.
• Boys with normal insulin levels had a higher testicular volume in prepuberty and postpuberty compared with those with hyperinsulinemia, whereas in peripuberty, boys with hyperinsulinemia had higher testicular volume compared with those with normal insulin levels.
• In postpuberty, adolescents with insulin resistance had lower testicular volume than those with normal insulin resistance. Type 2 diabetes did not influence testicular volume in any age group.(Monostra Endo Today 2022)

It is well known that the metabolic state of obesity and insulin resistance drive inflammation and hormonal dysregulation. Thus, it should be no surprise that we are seeing reproductive issues come into question.

From frontiers in Public Health: Diets high in unsaturated fats, whole grains, vegetables, and fish have been associated with improved fertility in both women and men. While current evidence on the role of dairy, alcohol, and caffeine is inconsistent, saturated fats, and sugar have been associated with poorer fertility outcomes in women and men. Furthermore, women and men with obesity [body mass index (BMI) ≥ 30 kg/m2] have a higher risk of infertility. (Panth et. al. 2022)

The likely pathophysiological cause of these fertility concerns is the food induced oxidate damage to mitochondria and the immune activation following the hyperinsulinemia, hyperglycemia and adiposity. These and other effects drive a pattern of hormonal dysregulation leading to smaller testis, ovaries that are cystic and other reproductive problems.


Dr. M

Monostra Endocrinology Today
Panth Frontiers in Public health