Differences in pituitary and testicular function between diabetic patients on insulin and oral anti-diabetic agents

Abstract

Summary.Pituitary responsiveness to thyrotrophin releasing hormone (TRH) and luteinizing hormone releasing hormone (LHRH) was studied in thirty one male diabetics, of whom sixteen were insulin-dependent and fifteen on oral ant• agents. Ten age-matched controls were also studied. TRH and LHRH were simultaneously administered intravenously, each in a small dose of 10 ~tg followed two hours later by 190 ~tg and 90 ~tg respectively. Basal hormone levels were measured in a further group of thirty six patients (twelve on insulin, twelve on oral agents and twelve on dietary restrictions alone).Higher thyrotrophin (TSH) response was observed following the small dose of TRH in the patients treated with oral agents than in the control subjects. The response of prolactin was lower in patients treated with oral agents compared with those treated with insulin. There was no difference in plasma 73 and T 4 levels in the patients treated with insulin or oral agents. Significantly higher basal growth hormone (GH) levels were observed in the diabetics. The insulin-dependent group showed a more marked response of GH to TRH/LHRH. No response was observed in the controls. Plasma testosterone levels were significantly lower in the oral agent group (13.8 nmol/1) than in the insulin group (19.4 nmol/1), patients on dietary restrictions (18.4 nmol/1) and the control subjects (19.0 nmol/1). The LH response to the smaller dose of LHRH was impaired in patients on insulin and oral agents. There was a significant difference in FSH response between impotent and sexually normal patients.

Semen Characteristics and Diabetes Mellitus: Significance of Insulin in Male Infertility

“…There were no significant differences in the serum concentrations of FSH and LH in the fertile normozoospermic men and the diabetic patients. Such results are in agreement with those of other authors [7,9,11,19,20,28,32,35,411 and suggest a normal functioning of the hypothalamic-pituitary leydig cell axis in subjects with type I diabetes mellitus. Our results coincide with those of other authors in the observation that serum testosterone levels in diabetic men are similar [19,281 or lower [2, 10, 151 than those shown by normal subjects.…”

“…Freetestosterone plasma levels are lower in impotent diabetics than in those who are not impotent or in normal men [3, 6, 271. These findings have not been confirmed [28,35,391.…”

“…The serum and urinary gonadotropins may be normal [7,9,11,19,20,28,32,35,391 or low [34] or have high-follicle-stimulating-hormone (FSH) levels [16,20,24,281 or high-LH levels [2,6,7,161. The response of FSH to stimulation with exogenous gonadatropin-releasing hormone (GnRH) in diabetic subjects may be normal [7,9,11,14,32, 391, below normal [41], or exaggerated [20,241.…”

Testosterone and the Cardiovascular System: A Comprehensive Review of the Clinical Literature

“…This association was first reported by 2 investigators in 1978 62–63 and since then has been confirmed by >20 additional studies. Recently, Ding et al 25 and Corona et al 26 performed 2 meta‐analyses that combined the results of the above‐mentioned studies and have produced similar results.…”

Diabetes mellitus and risk of prostate cancer: a meta-analysis

“…High testosterone levels have also been associated with an increased risk of prostate cancer [58]. Diabetic men have lower total and free testosterone levels [59,60,61,62,63,64,65]. Several studies have demonstrated a stepwise decrease in mean testosterone level per progressive increase in fasting plasma glucose throughout the whole range of plasma glucose [60,62,63].…”