|
| Study | Population | Results | Notes |
|
| European Male Aging Study (Cross-sectional) [10] | 3219 men ages 40 to 79 years. | (1) Overall prevalence of hypogonadism was 2.1%. (2) Hypogonadism increases with age 0.1% (40 to 49 yrs) 0.6% (50 to 59 yrs), 3.2% (60 to 69 yrs) 5.1% (70 to 79 yrs). (3) Prevalence is higher with increasing number of coexisting illnesses and BMI | Total testosterone <320 ng/dL (11 nmol/L), and free testosterone <64 pg/mL (220 pmol/l). (LCMS method) |
|
| The Baltimore Longitudinal Study of Aging (longitudinal) [8] | 890 men; average age 53.8 + 16 (samples during time period 1961 to 1995). | (1) Serum testosterone decreased at a fairly constant rate, independent of other clinical variables. (2) Average change of T is about 3.2 ng/dL (−0.124 nmol/L) per yr. (3) Incidence of hypogonadism:: ~20% in 60s, ~30% in 70s, and ~50% in 80s. | Androgen deficiency was defined as total testosterone less than 325 ng/dL. (RIA method) |
|
| The Massachusetts Male Aging Study (longitudinal) [12] | 1667 men aged 40 to 70 at baseline (1987–1989). | (1) Crude prevalence of androgen deficiency at baseline and followup is 6.0 and 12.3%. (2) Crude incidence rate of androgen deficiency was 12.3 per 1,000 P-Yr. (3) Prevalence and Incidence rate increased with age. (4) T declines associated with aging −10.1% decline in TT per decade −23.8% decline in FT per decade. | Total testosterone less than 200 ng/dL or total testosterone 200–400 ng/dL and free testosterone less than 8.91 ng/dL. (RIA method) |
|
| Boston Area Community Health Survey [9] | 1475 men ages of 30–79 yr; 47.3 ± 12.5 yr. | (1) Crude prevalence of symptomatic androgen deficiency was 5.6%. (2) Prevalence increases with age a. 3.1–7.0% in men less than 70 yr b. 18.4% among 70 yr old. (3) 24% of subjects had total testosterone less than 300 ng/dL, (4) 11% of subjects had free testosterone less than 5 ng/dL | Total concentration <300 ng/dL and free testosterone <5 ng/dL. |
|
| New Mexico Aging Process Study (longitudinal) [19] | 77 men in the age group 66–80. 15 years of the study period. | (1) Observed a longitudinal decline in T and an increase in LH and FSH. (2) The increasing levels of FSH suggest that hypogonadism in aging males is probably due to secondary hypogonadism. (3) Average rate of decrement in testosterone concentration is about 11 ng/dL (0.382 nmol/L) per year | Note, this study varies in rate of testosterone decline from the other studies |
|
