Sperm Count and Hypogonadism as Markers of General Male Health

Abstract

Background: Some evidence suggests that infertile men, who are at increased risk for hypogonadism, metabolic derangements, and osteoporosis, have higher long-term morbidity and mortality than controls, but data are scarce and not conclusive.

Objective: We tested whether semen quality and reproductive function could represent a marker of general male health.

Design, setting, and participants: A retrospective study of 5177 individuals from a prospectively collected database of 11516 males of infertile couples who had semen analysis in a tertiary university center.

Outcome measurements and statistical analysis: Of them, 5177 had all data for reproductive hormones, testis ultrasound, and biochemical determinations for glucose and lipid metabolism. Hypogonadism was defined as testosterone <10.5nmol/l and/or luteinizing hormone >9.4 IU/l. Individuals with a total sperm count of <10 million had genetic testing (karyotype, Y chromosome microdeletions, and CFTR gene mutations) and those with hypogonadism underwent dual-energy x-ray absorptiometry for bone mineral density. Descriptive statistics and odds ratio (OR) calculation were used.

Results and limitations: Men with a low sperm count (<39 million/ejaculate) are at a high risk of hypogonadism (OR 12.2, 95% confidence interval [CI] 10.2-14.6) and have higher body mass index, waist circumference, systolic pressure, low-density lipoprotein cholesterol, triglycerides, and homeostatic model assessment (HOMA) index; lower high-density lipoprotein cholesterol; and a higher prevalence of metabolic syndrome (OR 1.246, 95 CI 1.005-1.545). All data are worse in men with hypogonadism, but a low sperm count per se is associated with a poor metabolic parameter. Men with hypogonadism have lower bone mineral density and 51% prevalence of osteoporosis/osteopenia. Longitudinal studies are necessary to support these data.

Conclusions: This is the largest study with comprehensive evaluation of semen quality and reproductive function, etiology and risk factor determination, and metabolic, cardiovascular, and osteoporosis risk assessment, performed in men referred for fertility evaluation. A low sperm count is associated with poorer metabolic, cardiovascular, and bone health. Hypogonadism is mainly involved in this association, but a low sperm count in itself is a marker of general health.

Patient summary: This large study evaluated semen quality, reproductive function, and metabolic risk in men referred for fertility evaluation, and showed that a man's semen count is a marker of his general health. Men with low sperm counts are more likely than those with normal sperm counts to have greater body fat, higher blood pressure, higher "bad" (low-density lipoprotein) cholesterol and triglycerides, and lower "good" (high-density lipoprotein) cholesterol. They also have a higher frequency of metabolic syndrome and insulin resistance, a condition that can lead to diabetes. Men with low sperm counts had a 12-fold increased risk of hypogonadism or low testosterone levels, and half of them had osteoporosis or low bone mass. Fertility evaluation gives men the unique opportunity for health assessment and disease prevention.

Keywords: Azoospermia; Hypogonadism; Infertility; Male infertility; Metabolic syndrome; Oligozoospermia; Osteoporosis; Semen; Testosterone.