Characteristics of Androgen Deficiency in Late-onset Hypogonadism: Results from the European Male Aging Study (EMAS)
Introduction: Middle-aged and elderly men can develop late-onset hypogonadism (LOH), as well-defined as signs and symptoms of low T and low testosterone (T) levels. This study was undertaken to find objective biochemical and end-organ evidence of androgen deficiency. It was done in men who had been diagnosed with LOH by following the study authors' previously published criteria.
Methods: The European Male Aging Study has 2,966 community-dwelling men in it; they are ages 40 to 79 years, and they live in 8 European countries. This study used cross-sectional data from that group.
The main outcome measures were:
- waist circumference
- body mass index
- muscle mass
- physical activity
- cardiovascular disease
- estimated heel bone mineral density
- insulin sensitivity
- insulin resistance index
- metabolic syndrome
Results: Of the men in the study, 63 (2.1%) were classified at LOH; 36 of them had moderate LOH, and 27 had severe LOH. In comparison to eugonadal men, these 63 men were older and more obese. Additionally, in proportion to the graded T deficiency, these LOH men had lower muscle mass, estimated heel bone mineral density, and hemoglobin. They were in poorer health overall.
Moderate and severe LOH were both associated with lower hemoglobin, mid-upper arm circumference, estimated heel bone mineral density, and physical function (as measured with the Short Form-36). Both moderate and severe LOH also showed slower gait speed and poorer overall health.
Larger waist circumference was associated with severe LOH only (β = 1.93 cm; 0.04-3.81), as was insulin resistance ( β = 2.81; 1.39-4.23). Severe LOH was also associated with metabolic syndrome (odds ratio 9.94; 2.73-36.22). All these associations were seen after adjusting for confounders.
If men had low T only—regardless of their signs and symptoms—there was a lower association with the same main outcome measures.
Conclusions: This study supports the existence of LOH but only in a minority of aging men—particularly those with testosterone levels of < 8 nmol/L. Late-onset hypogonadism is associated with multiple end-organ effects (similar to androgen deficiency).
The clinical significance of age-related testosterone decline continues to be debated. The syndrome of late-onset hypogonadism (LOH), including clinical and biochemical evidence of androgen deficiency, remains elusive.
The European Male Aging Study evaluated 2,966 men aged 40-79 years old in 8 European countries for LOH. The purpose of this cross-sectional study was to find objective biochemical and end-organ evidence of androgen deficiency for this diagnosis. Surprisingly, only 63 (2.1%) of these men were classified as LOH based on having low testosterone and at least three sexual symptoms.
The LOH men were more likely to have decreased hemoglobin, bone density, muscle mass, and were in overall poorer health. Furthermore, those classified as severe LOH had significantly larger waist circumferences, increased insulin resistance, and were more likely to have metabolic syndrome. These features were more pronounced in those with more severe LOH, showing a graded relationship with degree of testosterone deficiency. The prevalence of LOH was highest in those with testosterone levels below 8 nmol/L.
This study indicates that the syndrome of LOH exists in a minority of middle-aged and elderly males. When present, it is associated with poor overall health.