Decline in sexual activity in ageing men: correlation with sex hormone levels and testicular changes

Rheumatoid arthritis, the contraceptive pill, and androgens

Evidence is accumulating that low androgen concentrations are a cause of rheumatoid arthritis. This would explain a number of established features of the epidemiology of the disease. These include: (a) the variation of disease activity with pregnancy; (b) the variation of age at onset by sex; (c) the variation by sex with HLA-B15; (d) the association with bone mineral density; and (e) the differing time trends in incidence rates by sex. It is argued, moreover, that if one makes a plausible assumption--namely, that women who choose oral contraceptives have high androgen concentrations at the time they first make this choice--then an explanation becomes available for the confusion about the relation between rheumatoid arthritis and oral contraception. Grounds are adduced for that assumption. If this line of reasoning is substantially correct it also has implications for the relations between rheumatoid arthritis and smoking and consumption of alcohol.

An examination of research design effects on the association of testosterone and male aging: results of a meta-analysis

The study of testosterone is likely to be prominent in future epidemiological work on endocrine function and the clinical treatment of age-related diseases. Thus, understanding the hormonal changes involved in the normal male aging process will be critical. Using techniques of meta-analysis, the authors examined 88 published studies of the age-testosterone relation in men. These studies reported conflicting results: age-testosterone correlations ranged from -0.68 to +0.68. In cross-study comparisons, certain research design characteristics (e.g. time of day of blood sampling) and various sample characteristics (e.g. volunteers vs patients as subjects) were related to both mean testosterone level and the slope of the age-testosterone relation. For example, for subgroups of subjects that did not exclude ill men, the mean testosterone levels were low, and did not decline with age. Subgroups that included only healthy subjects, in contrast, had higher overall testosterone levels and showed a decline of testosterone with age. Implications of these results for design, analysis and reporting of future epidemiologic studies will be discussed. These results also illustrate the utility of meta-analysis for research with the aged.

The questionable physiologic and epidemiologic basis for a male climacteric syndrome: preliminary results from the Massachusetts Male Aging Study

This paper examines the physiologic and epidemiologic evidence for a widely discussed syndrome termed either 'mid-life crisis', 'male menopause', 'male climacteric', or increasingly, 'andropause'. The paper is divided into 2 parts: (1) a review of evidence from physiologic studies conducted over the last decade that examine endocrine function in aging males; (2) a description of the salient features of an ongoing multidisciplinary epidemiologic study (the Massachusetts Male Aging Study) of a sample of approximately 1700 men aged 40-69 yr, randomly sampled from the general population. This study is markedly different in size and content from studies conducted to date. Preliminary findings suggest that age per se may be a relatively unimportant contributor to endocrine variability and that anthropometrics and life style phenomena may be at least as important.

Erectile failure in the aged: evaluation and treatment

With aging, there are changes in both libido and erectile function. Although the majority of aged men remain interested in sex, less than 15% report continued sexual intercourse. The cause of this "libido-potency gap" is due primarily to erectile failure. Penile erection is dependent upon a complex interaction of the autonomic nervous system, cardiovascular system, and local neurotransmitters such as acetylcholine and vasoactive intestinal polypeptide. Sexual stimulation causes augmented blood flow into the corpora cavernosa, and restricted outflow, resulting in penile rigidity. With aging, there is a decline in gonadal steroids, nerve conduction velocity, and vascular compliance, any of which could interfere with normal erections. When disease is superimposed on the normal changes of aging, erectile function is further impaired. Evaluation of an elderly male with impotence may consist of a detailed drug history and trial of alternate therapy, as in the case of adverse drug reactions. More often, evaluation entails hormonal assays, penile vascular assessment, neurologic assessment, and an evaluation of nocturnal erectile function. Based on the results of these assessments, appropriate treatment alternatives can be chosen. With the availability of multiple treatment options, patients and physicians can now choose from a range of noninvasive or invasive alternatives depending upon the etiology, associated disorders, and preference of the patient.

A cross-national comparison of the relative influence of male and female age on the frequency of marital intercourse

Parallel analyses of recent data from the United States, Thailand, Belgium, and Japan all confirm the finding that female age and not male age is the more important contributor to the decline in frequency of marital intercourse during the childbearing ages. The most probable explanation is the decline in female (but not male) androgen levels during the age span examined.