“Damnant quod non intelligent”
Dr Tevaarwerk has suggested that pharmaceutical association on the part of the Hypogonadism in Men (HIM) study authors invalidates the results. While I applaud academic rigor in review of literature, to propose one “stop reading” if the authors disclose pharmaceutical industry association boarders on paranoia.
The reality is that most authors, myself included, have at some point accepted speaking honoraria, consultancy fees, or research funding from industry. If his suggestion were rigorously applied this would exclude the vast majority of all peer-reviewed publications.
The HIM study has provided us with useful data regarding the prevalence of hypogonadism and specific disease associations. Indeed, the HIM study contributed to the Endocrine Society recommendations for case finding of hypogonadism in men with type 2 diabetes. To endocrinologists, the Endocrine Society is the most prestigious, academically rigorous association we have, and any Endocrine Society practice recommendations are highly scrutinized.
Dr Tevaarwerk claims that the HIM study overestimates the prevalence of hypogonadism in men. In his letter he has misquoted the Massachusetts Male Aging Study (MMAS). The HIM study reported a hypogonadism prevalence of 38.7% in men over age 45. The age range was 45 to 96 with a mean age of 60.5 years.
Dr Tevaarwerk’s use of the crude 6.0% prevalence in the MMAS for his calculation is inappropriate, as it does not compare similarly aged men. If one uses the reported prevalence at baseline and follow-up for the closest comparable age group of 60 to 70 years, the results are 9.4% and 11.5% respectively, or an average of 10.5%.
It is important to note that the MMAS had some limitations. First, the men included in this study had to pass an unvalidated screening questionnaire or no testosterone samples were measured, and the questionnaire used did not correlate with the testosterone results.
Second, the MMAS cohort has been preselected to include healthy men. By excluding men who did not pass the questionnaire, or had comorbid illnesses, many of which have an associated increased risk ofhypogonadism, the MMAS has an inherent selection bias of decreased detection.
Third, it has been postulated that the prevalence of hypogonadism is increasing. The MMAS dates back to 1995, and reported that the prevalence of hypogonadism increased over the 9 years studied. It has been postulated that this may be related to an increase in obesity. The HIM study was published in 2006 and hence an increased prevalence with time would be a consistent trend.
The HIM study is also consistent with many other prevalence studies. In men aged 60 to 69 years, the Baltimore Longitudinal Study reported a prevalence of a low free androgen index of 34%; the Mayo Clinic reported a low bioavailable testosterone (BAT) prevalence of 20%; and the Canadian Physician Study7 reported a prevalence of low BAT of 45%. Hence, it is the MMAS that is in fact the outlier.
Dr Tevaarwerk suggested that the HIM data set does not represent the population targeted in my article. I believe just the opposite is true as the HIM measured all men in a primary care setting without excluding patients that we now know have a higher pretest probability of hypogonadism.
Dr Tevaarwerk states that testosterone levels should be measured before 8 a.m. In fact, the accepted time for measurement is from 7 a.m. to 11 a.m., although any time prior to 10 a.m. has been the standard in British Columbia.
Dr Tevaarwerk suggests that “gradually declining testosterone levels may be part of the normal aging process.” While some decline in bodily functions with aging is expected, when a physiological state, in this case hypogonadism, has been associated with an increased risk of osteoporosis, osteoporotic fractures, the metabolic syndrome, type 2 diabetes, and shortened life expectancy, that is no longer “normal aging” but a disease condition worthy of medical attention.
As an analogy, would Dr Tevaarwerk suggest not treating older patients with hypothyroidism? After all, fatigue is common and perhaps the norm in the elderly. Eleven percent of men and 16% of women have an elevated TSH by the age of 65 to 74 years. Would he therefore state that hypothyroidism is so common that physicians should consider this to be normal aging and leave these patients untreated?
In the absence of long-term, randomized, placebo-controlled outcome studies, treatment of hypothyroidism has historically been based on resolution of symptoms and is today the standard of care. To treat hypogonadism differently than hypothyroidism would seem illogical and based only on an unjustified bias against testosterone.
—Richard Bebb, MD