Context: The diagnosis of late-onset hypogonadism (LOH) in older men with age-related declines in testosterone (T) is currently not well characterized.
Objective: Our objective was to investigate whether different forms of hypogonadism can be distinguished among aging men.
Design: The study was a cross-sectional survey on 3369 community-dwelling men aged 40-79 yr in eight European centers.
Methods: Four groups of subjects were defined: eugonadal (normal T and normal LH), secondary (low T and low/normal LH), primary (low T and elevated LH), and compensated (normal T and elevated LH) hypogonadism. Relationships between the defined gonadal status with potential risk factors and clinical symptoms were investigated by multilevel regression models.
Results: Among the men, 11.8, 2.0, and 9.5% were classified into the secondary, primary, and compensated hypogonadism categories, respectively. Older men were more likely to have primary [relative risk ratio (RRR) = 3.04; P < 0.001] and compensated (RRR = 2.41; P < 0.001) hypogonadism. Body mass index of 30 kg/m(2) or higher was associated with secondary hypogonadism (RRR = 8.74; P < 0.001). Comorbidity was associated with both secondary and primary hypogonadism. Sexual symptoms were more prevalent in secondary and primary hypogonadism, whereas physical symptoms were more likely in compensated hypogonadism.
Conclusions: Symptomatic elderly men considered to have LOH can be differentiated on the basis of endocrine and clinical features and predisposing risk factors. Secondary hypogonadism is associated with obesity and primary hypogonadism predominately with age. Compensated hypogonadism can be considered a distinct clinical state associated with aging. Classification of LOH into different categories by combining LH with T may improve the diagnosis and management of LOH.