Accounting for racial/ethnic variation in bone mineral content and density: the competing influences of socioeconomic factors, body composition, health and lifestyle, and circulating androgens and estrogens.

UNLABELLED: The relative importance of various contributors to racial/ethnic variation in BMC/BMD is not established. Using population-based data, we determined that body composition differences (specifically skeletal muscle and fat mass) are among the strongest contributors to these variations. INTRODUCTION: Racial/ethnic variation in fracture risk is well documented, but the mechanisms by which such heterogeneity arises are poorly understood. We analyzed data from black, Hispanic, and white men enrolled in the Boston Area Community Health/Bone (BACH/Bone) Survey to determine the contributions of risk factors to racial/ethnic differences in bone mineral content (BMC) and density (BMD). METHODS: In a population-based study, BMC, BMD, and body composition were ascertained by DXA. Socioeconomic status, health history, and dietary intake were obtained via interview. Hormones and markers of bone turnover were obtained from non-fasting blood samples. Multivariate analyses measured percentage reductions in estimated racial/ethnic differences in BMC/BMD, accompanying the successive removal of covariates from linear regression models. RESULTS: Black men demonstrated greater BMC than their Hispanic and white counterparts. At the femoral neck, adjustment for covariables was sufficient to reduce these differences by 46% and 35%, respectively. While absolute differences in BMC were smaller at the distal radius than femoral neck, the proportionate reductions in racial/ethnic differences after covariable adjustment were comparable or greater. Multivariate models provided evidence that lean and fat mass, serum 25(OH)D, osteocalcin, estradiol, and aspects of socioeconomic status influence the magnitude of racial/ethnic differences in BMC, with lean and fat mass providing the strongest effects. Results for BMD were similar, but typically of lesser magnitude and statistical significance. CONCLUSIONS: These cross-sectional analyses demonstrate that much of the racial/ethnic heterogeneity in measures of bone mass and density can be accounted for through variation in body composition, diet, and socio-demographic factors.

Relative contributions of multiple determinants to bone mineral density in men.

SUMMARY: Focus on individual risk factors for osteoporosis could allocate disproportionate attention to trivial relationships. We tested many recognized risk factors of osteoporosis for their association with bone mineral density (BMD) in multivariate models among men. Lean mass accounted for the most variance, with substantially less accounted for by demographic, strength, and health factors. INTRODUCTION: Osteoporosis in men has gained recognition as a public health problem, generating an interest in the search for risk factors. Isolation of individual risk factors could allocate disproportionate attention to relationships that may be of limited consequence. METHODS: The Boston Area Community Health/Bone (BACH/Bone) Survey is a population-based study of randomly selected community-dwelling men (age, 30-79 years). BMD and lean mass were measured by dual X-ray absorptiometry. Socioeconomic status, health history, and lifestyle factors were obtained via interview. Hormone levels and markers of bone turnover were obtained from non-fasting blood samples. Multivariate analyses measured relative contributions of covariates to femoral neck (hip), one-third distal radius (wrist), and lumbar spine BMD. RESULTS: Factors positively associated with BMD in multivariate models at the three sites were black race and appendicular lean mass. Asthma was consistently negatively associated. Various other risk factors also contributed significantly to each of the individual sites. R (2) values for the hip, wrist, and spine were 41%, 30%, and 24%, respectively. Lean mass accounted for the most explained variance at all three sites. CONCLUSIONS: These data emphasize the limitation of focusing on individual risk factors and highlight the importance of potentially modifiable lean mass in predicting BMD.

Serum 25-hydroxyvitamin D and bone mineral density among Hispanic men.

UNLABELLED: There are few data on the skeletal health of Hispanic men. We observed differences in vitamin D deficiency and low BMD between Hispanic ethnic subgroups that persisted with adjustment for risk factors. Our data indicate a substantial burden of low BMD and vitamin D deficiency among Hispanic men. INTRODUCTION: Disparities within ethnic groups are generally ignored, but in evolving populations they may have implications for public health. We examined ethnic variation in serum 25-hydroxyvitamin D [25(OH)D] and bone mineral density (BMD) among Hispanic American men. METHODS: Three hundred and fifty-eight Hispanic males 30 to 79 years of age were studied. Logistic regression models assessed variation in odds of vitamin D deficiency (<20 ng/mL) and low BMD (T-score<-1) by ethnicity, with and without adjustment for risk factors (age, smoking, occupation, physical activity, body mass index, and sunlight exposure). RESULTS: Vitamin D deficiency was most common among Puerto Rican (26%), compared with Dominican (21%), Central American (11%), and South American (9%) men. Percentages with low BMD were: South American (44%), Puerto Rican (34%), Dominican (29%), and Central American (23%). Adjustment for age and risk factors failed to account for Hispanic subgroup differences in vitamin D deficiency and low BMD. Population estimates indicate a substantial burden of low BMD and vitamin D deficiency among Hispanic men. CONCLUSIONS: Our findings underscore the importance of examining the skeletal health of Hispanic subgroups, and suggest that a considerable number of Hispanic men may be at elevated risk of fracture and vitamin D deficiency.

Age trends in proximal femur geometry in men: variation by race and ethnicity.

UNLABELLED: Data on bone architecture in diverse male populations are limited. We examined proximal femur geometry in 1,190 black, Hispanic, and white men. Cross-sectional analyses indicate greatest bone strength among black men, and greater age-related differences in bone strength among Hispanic men than other subjects at the narrow neck and intertrochanter regions of the proximal femur. INTRODUCTION: Although race/ethnic differences in bone mass are well-documented, less is known about differences in bone architecture. We examined proximal femur geometry in a diverse, randomly-sampled population of 1,190 community-dwelling men (age 30-79 y). METHODS: Dual X-ray absorptiometry scans were obtained for 355 black, 394 Hispanic, and 441 white subjects. Measures were obtained for the narrow neck (NN), intertrochanter (IT) and shaft regions of the proximal femur via hip structural analysis. Analyses considered bone mineral density (BMD, g/cm2), outer diameter (cm), cross-sectional area (CSA, cm2), section modulus (Z, cm3), and buckling ratio (BR). Results were adjusted for height, weight and physical activity level. RESULTS: Black subjects exhibited greater age-specific BMD, CSA and Z, than their white counterparts. For instance, at age 50 y, NN BMD was approximately 11% higher among black men (p < 0.001). Hispanic men exhibited sharper age-related differences in NN and IT BMD than did others. IT BMD, for instance, decreased by 2.4% with 10 y age among Hispanic subjects, but had virtually no age trend in others (p < 0.001). CONCLUSIONS: These results imply greater bone strength among black American men than among their white counterparts, and may indicate elevated fracture risk among older Hispanic American subpopulations.

The relationship between body composition and bone mineral content: threshold effects in a racially and ethnically diverse group of men.

UNLABELLED: We examined BMC and body composition in 1,209 black, Hispanic, and white men. Weight, BMI, waist circumference, and fat mass were associated with BMC only up to certain thresholds, whereas lean mass exhibited more consistent associations. The protective influence of increased weight appears to be driven by lean mass. INTRODUCTION: Reduced body size is associated with decreased bone mass and increased fracture risk, but associations in men and racially/ethnically diverse populations remain understudied. We examined bone mineral content (BMC) at the hip, spine, and forearm as a function of body weight, body mass index (BMI), waist circumference, fat mass (FM), and nonbone lean mass (LM). METHODS: The design was cross-sectional; 363 non-Hispanic black, 397 Hispanic, and 449 non-Hispanic white residents of greater Boston participated (N = 1,209, ages 30-79 y). BMC, LM, and FM were measured by DXA. Multiple linear regression was used to describe associations. RESULTS: Weight, BMI, waist circumference, and FM were associated with BMC only up to certain thresholds. LM, by contrast, displayed strong and consistent associations; in multivariate models, femoral neck BMC exhibited a 13% increase per 10 kg cross-sectional increase in LM. In models controlling for LM, positive associations between BMC and other body composition measures were eliminated. Results did not vary by race/ethnicity. CONCLUSIONS: The protective effect of increased body size in maintaining bone mass is likely due to the influence of lean tissue. These results suggest that maintenance of lean mass is the most promising strategy in maintaining bone health with advancing age.

Sources of variation in physician adherence with clinical guidelines: results from a factorial experiment.

BACKGROUND: Health services research has documented the magnitude of health care variations. Few studies focus on provider level sources of variation in clinical decision making-for example, which primary care providers are likely to follow clinical guidelines, with which types of patient. OBJECTIVES: To estimate: (1) the extent of primary care provider adherence to practice guidelines and the unconfounded influence of (2) patient attributes and (3) physician characteristics on adherence with clinical practice guidelines. DESIGN: In a factorial experiment, primary care providers were shown clinically authentic video vignettes with actors portrayed different "patients" with identical signs of coronary heart disease (CHD). Different types of providers were asked how they would manage the different "patients" with identical CHD symptoms. Measures were taken to protect external validity. RESULTS: Adherence to some guidelines is high (over 50% of physicians would follow a third of the recommended actions), yet there is low adherence to many of them (less than 20% would follow another third). Female patients are less likely than males to receive 4 of 5 types of physical examination (p < .03); older patients are less likely to be advised to stop smoking (p < .03). Race and SES of patients had no effect on provider adherence to guidelines. A physicians' level of experience (age) appears to be important with certain patients. CONCLUSIONS: Physician adherence with guidelines varies with different types of "patient" and with the length of clinical experience. With this evidence it is possible to appropriately target interventions to reduce health care variations by improving physician adherence with clinical guidelines.

Race/ethnic differences in bone mineral density in men.

UNLABELLED: The epidemiology of osteoporosis in male and minority populations is understudied. We compared BMD in 1,209 Black, Hispanic, and White men. Black men exhibited higher BMD than Hispanic or White men. Age-related BMD decreases were greatest among Hispanic men. Results may help explain variation in hip fracture rates by race/ethnicity. INTRODUCTION: The epidemiology of osteoporosis in male and minority populations is understudied. To address this concern, we conducted a study of skeletal health in a diverse population of adult males. METHODS: A total of 367 Black, 401 Hispanic, and 451 White men aged 30-79 years were randomly sampled from Boston, MA. Bone densitometry (bone area (BA), bone mineral content (BMC), and bone mineral density (BMD)) at the whole body, hip, lumbar spine, and forearm was performed. Multiple regression analyses on 1,209 men with available data were used to describe race/ethnic group-specific means (height- and age-adjusted) and age trends (height-adjusted) in BMC, BA, and BMD. Results were weighted to represent the Boston male population aged 30-79 years. RESULTS: Black men had greater BMC and BMD than Hispanic or White men. Femoral neck BMD was 5.6% and 13.3% higher in Black men than in Hispanic and White men, respectively. Differences between Hispanic and White subjects were restricted to the hip. Age-related declines in BMC and BMD were significantly steeper among Hispanic than Black or White men. CONCLUSIONS: Differences in BMC and BMD could explain variation in fracture rates among Black, Hispanic, and White men. The steeper age-related BMD decline in Hispanic men is of particular concern.

Prevalence of foot and ankle conditions in a multiethnic community sample of older adults.

The prevalence of foot and ankle disorders was determined in a community-based, multiethnic (non-Hispanic White, African American, and Puerto Rican) random sample of 784 community-dwelling adults aged 65 or more years in 2001-2002 in Springfield, Massachusetts. Overall, the five most common conditions were toenail disorders (74.9%), lesser toe deformities (60.0%), corns and calluses (58.2%), bunions (37.1%), and signs of fungal infection, cracks/fissures, or maceration between toes (36.3%); 30.9% had some tenderness to palpation of the foot or ankle, and 14.9% had ankle joint pain on most days in the past 4 weeks. Toenail conditions, fungal symptoms, and ulcers or lacerations were more common in men, while bunions and corns and calluses were more common in women (p < 0.001). Significant racial/ethnic differences, independent of education or gender, were found for the prevalence of most toe deformities and flat feet, as well as for corns and calluses, fungal signs, edema, ankle joint pain, tenderness to palpation, and sensory loss. Foot and ankle disorders are common in these older adults. Examination of their prevalence in different segments of the community may inform future studies to determine etiology and means of prevention.

Testosterone level, androgen receptor polymorphism, and depressive symptoms in middle-aged men.

BACKGROUND: Testosterone (T) level declines progressively with age. Psychiatric symptoms of T deficiency (e.g., dysphoria, fatigue, irritability, low libido) are also symptoms of depression, and appear to be variably expressed. METHODS: We assessed independent measures of hypothalamic-pituitary-gonadal axis functioning, i.e., total T level and androgen receptor (AR) CAG repeat length (CAG RL), a genetic trait marker associated with AR function; and depression (diagnosed by above-threshold score on the Center for Epidemiologic Studies-Depression Scale [CES-D]) in 1000 men (mean age = 62.6 years; SD = 8.3) who participated in the Massachusetts Male Aging Study. RESULTS: There were 110 (11%) men with "depression" (CES-D score > or = 16) in the analysis sample. Neither total T level nor CAG RL was associated with depression in bivariate analyses. Among men with shorter CAG RLs, the percentage of men with depression was 21.6% in the lowest subgroup of total T (defined by quintiles) and 4.2% in the highest subgroup of total T. This was confirmed in simple logistic regression models with depression as the dependent variable and continuous total T as the predictor, run separately within the three CAG RL subgroups: depression was significantly and inversely associated with total T in men with shorter CAG RLs but not in men with moderate and longer CAG RLs. CONCLUSIONS: CAG isotype, a genetic trait marker of androgen receptor function, may mediate the expression of the central nervous system effects of T deficiency in men.

Risk factors for clinical benign prostatic hyperplasia in a community-based population of healthy aging men.

We defined risk factors for a clinical diagnosis of benign prostatic hyperplasia (BPH) among subjects of the population-based Massachusetts Male Aging Study. In 1987-89 1709 men aged 40-70 provided baseline risk factor data and were followed for a mean of 9 years; 1019 men without prostate cancer provided follow-up data. We classified men with clinical BPH at follow-up if they reported (1) frequent or difficulty urinating and were told by a health professional that they had an enlarged or swollen prostate or (2) if they reported having surgery for BPH. At follow-up the prevalence of clinical BPH was 19.4%, increasing from 8.4% of men aged 38-49 years to 33.5% of men aged 60-70 years (P < 0.001 for trend). Elevated free PSA levels (age- and total PSA-adjusted OR, top vs. bottom quartile ng/mL 4.4, 95% CI 1.9-10.5), heart disease (age-adjusted OR 2.1, CI 1.3-3.3), and use of beta-blocker medications (OR 1.8, CI 1.1-3.0) increased odds for BPH, while current cigarette smoking (OR 0.5, CI 0.3-0.8) and high levels of physical activity (top vs. bottom quartile kcals/day OR 0.5, CI 0.3-0.9) decreased odds of BPH. All but the medication effects persisted in fully adjusted multivariable models. Total or fat calorie intake, sexual activity level, alcohol intake, body mass index, waist-hip ratio, diastolic blood pressure, a history of diabetes, hypertension, vasectomy, or serum levels of androgens or estrogens did not individually predict clinical BPH. We conclude that physical exercise and cigarette smoking appear to protect against development of clinical BPH. Elevated free PSA levels predict clinical BPH independent of total PSA levels. Risk associated with heart disease does not appear to be due solely to detection bias or to effects of heart disease medications. A wide variety of other characteristics appear to have no influence on risk for clinical BPH.

Drug therapy and prevalence of erectile dysfunction in the Massachusetts Male Aging Study cohort.

STUDY OBJECTIVE: To examine the association of commonly used drugs with erectile dysfunction (ED) at two time points. DESIGN: Population-based, cross-sectional, survey analysis. PARTICIPANTS: Randomly selected cohort of men in the Massachusetts Male Aging Study (MMAS) that included 1476 men for the baseline (1987-1989) and 922 for the follow-up (1995-1997) analyses. INTERVENTION: Crude associations between specific drug categories were examined with chi2 statistics. Logistic regression analysis was used to separate the effect of drugs from the influence of heart disease, hypertension, untreated diabetes, or depressive symptoms. MEASUREMENTS AND MAIN RESULTS: In the MMAS, medical history, current drug use, and erectile function status were ascertained with in-home interviews. In unadjusted analyses, thiazide and nonthiazide diuretics, beta-blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, benzodiazepines, digitalis, nitrates, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, and histamine2 receptor antagonists were associated with prevalent ED. Adjustment for comorbidities and health behaviors attenuated these associations, with only nonthiazide diuretics and benzodiazepines remaining statistically significant. CONCLUSION: Several common drugs may increase prevalence of ED; however, additional data from larger populations are needed to determine whether these associations are independent of underlying health conditions and to explore the effects of dosage and duration of use.

Are serum hormones associated with the risk of prostate cancer? Prospective results from the Massachusetts Male Aging Study.

OBJECTIVES: To determine whether prediagnostic serum hormones are predictive of prostate cancer risk in a sample of men 40 to 70 years old at baseline. METHODS: Seventeen serum hormones, including androgens, estrogens, and adrenal and pituitary hormones, were measured at baseline (1987 to 1989) and used to predict incident prostate cancer by follow-up (1995 to 1997) using data from the Massachusetts Male Aging Study, a prospective, population-based random sample. RESULTS: Seventy men (4%) of 1576 were diagnosed with prostate cancer between the baseline and follow-up periods (approximately 8 years). None of the hormones were associated with prostate cancer risk except for androstanediol glucuronide (AAG), which exhibited a nonlinear, inverse relationship with prostate cancer (P <0.003) when age, body mass index, alcohol use, dihydrotestosterone, and total prostate-specific antigen were controlled for. Men in the second, third, and fourth quartiles of AAG relative to the first were less likely to be diagnosed with prostate cancer, although only the comparison of the second versus the first achieved statistical significance (odds ratio 0.2, 99% confidence interval 0.04 to 0.6). No dose-response relationships were observed. CONCLUSIONS: The lack of association with most hormones and the nonlinear association with AAG calls into question whether serum hormones collected during midlife are risk factors for prostate cancer.

Low dehydroepiandrosterone and ischemic heart disease in middle-aged men: prospective results from the Massachusetts Male Aging Study.

The adrenal steroid dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) have been characterized as "protective" against ischemic heart disease (IHD), especially in men, on the basis of sparse epidemiologic evidence. The authors used data from the Massachusetts Male Aging Study, a random sample prospective study of 1,709 men aged 40-70 years at baseline, to test whether serum levels of DHEA or DHEAS could predict incident IHD over a 9-year interval. At baseline (1987-1989) and follow-up (1995-1997), an interviewer-phlebotomist visited each subject in his home to obtain comprehensive health information, body measurements, and blood samples for hormone and lipid analysis. Incident IHD between baseline and follow-up was ascertained from hospital records and death registries, supplemented by self-report and evidence of medication. In the analysis sample of 1,167 men, those with serum DHEAS in the lowest quartile at baseline (<1.6 microg/ml) were significantly more likely to incur IHD by follow-up (adjusted odds ratio = 1.60, 95 percent confidence interval: 1.07, 2.39; p = 0.02), independently of a comprehensive set of known risk factors including age, obesity, diabetes, hypertension, smoking, serum lipids, alcohol intake, and physical activity. Low serum DHEA was similarly predictive. These results confirm prior evidence that low DHEA and DHEAS can predict IHD in men.

Family history and the risk of prostate cancer.

OBJECTIVES: Several studies have identified prostate cancer family history as a risk factor for prostate cancer incidence, typically associated with a twofold to fourfold increase in risk. A family history of breast cancer has also been implicated. We investigated the associations between prostate cancer incidence and family histories of prostate and breast cancer, controlling for possible confounding due to environmental factors. METHODS: Data from the random sample-based Massachusetts Male Aging Study cohort (1987 to 1997) were used. Incidence rates were calculated as the number of cases per person-year of follow-up. Covariates were adjusted for using Poisson regression. RESULTS: Among 1149 men with an average of 8.7 person-years of follow-up, 57 were diagnosed with prostate cancer, 110 men reported a prostate cancer family history, and 157 reported a breast cancer family history. The age-adjusted relative risk (RR) of prostate cancer incidence associated with prostate cancer family history was 3.29 (95% confidence interval [CI] 1.82 to 5.94). No evidence of heterogeneity was found across age levels (P = 0.83). Additional adjusting for environmental factors such as smoking, alcohol use, body mass index, physical activity, education, sexually transmitted disease history, diet, and hormone levels yielded a slightly higher RR (3.78, 95% CI 1.96 to 7.28). No association with a family history of breast cancer was evident (RR = 1.18, 95% CI 0.51 to 2.43). CONCLUSIONS: We found an association between prostate cancer incidence and a family history of prostate cancer, independent of environmental factors. No association with a family history of breast cancer was evident.

Measurement of erectile dysfunction in population-based studies: the use of a single question self-assessment in the Massachusetts Male Aging Study.

A concise, reliable means of assessing erectile dysfunction (ED) in large, multidisciplinary population-based studies is needed. A single, direct question for self-assessed ED was assessed in the population-based sample of the Massachusetts Male Aging Study (MMAS). Of the 1156 respondents to the 1995-97 MMAS follow-up evaluation, 505 were randomly selected to complete either the International Index of Erectile Function (IIEF) (n = 254), or the Brief Male Sexual Function Inventory (BMSFI) (n = 251), in addition to the single question self-assessment. The proportion not classified due to missing data was MMAS-9%, BMSFI-8%, and IIEF-18%. The single question correlated well with these other measures (r = 0.71-0.78, P < 0.001). Prevalence was similar to that based on the IIEF, agreement was moderate (kappa = 0.56-0.58), and associations with previously identified risk factors were similar for each classification. Thus, the MMAS single question may be a practical tool for population-based studies where detailed clinical measures of ED are impractical.

The worldwide prevalence and epidemiology of erectile dysfunction.

This paper: (i) describes the worldwide prevalence of erectile dysfunction (ED); (ii) presents age-specific incidence rates for ED in the US; (iii) summarizes some key epidemiologic correlates of ED in the general population; and (iv) considers the possibility that ED may be a biobehavioral marker (sentinel event) of subsequent cardiovascular disease in men. Clinical, anthropometric, life style and hormonal data are presented from the milestone Massachusetts Male Aging Study (MMAS), a large (over 1000) prospective cohort of randomly sampled community-dwelling, normally aging men. Newly updated population prevalence and (more importantly) age-specific incidence rates are reported. We also estimate the likely magnitude of ED that will accompany the worldwide globalization of aging. Key correlates (predictors) of incident ED, especially vasculogenic influences, are identified and discussed. In conclusion, ED is a common biobehavioral phenomenon and there are strong physiological and epidemiological reasons for considering it a major marker (or predictor) of subsequent cardiovascular disease in men. International Journal of Impotence Research (2000) 12, Suppl 4, S6-S11.

Relation between psychosocial risk factors and incident erectile dysfunction: prospective results from the Massachusetts Male Aging Study.

Erectile dysfunction (ED) is recognized as a major public health problem. ED may be due to a wide range of factors, but recent work has focused on the medical and physical etiology of ED. The importance of psychosocial risk factors should not be dismissed, however, and several cross-sectional studies have reported associations between ED and depression, anger, and dominance. Whether these factors are prospectively associated with the risk of ED has yet to be established. Longitudinal data obtained from 776 respondents in the Massachusetts Male Aging Study (1987-1997) were used to examine whether the presence of depressive symptoms, the way in which anger was expressed, or the trait of dominance independently contributed to the risk of ED 8.8 years later. The results suggest that new cases of ED are much more likely to occur among men who exhibit a submissive personality. The implications of these findings are discussed.

Socioeconomic factors and incidence of erectile dysfunction: findings of the longitudinal Massachussetts Male Aging Study.

Despite the well-documented relationship of socioeconomic factors (SEF) to various health problems, the relationship of SEF to erectile dysfunction (ED) is not well understood. As such, the goals of this paper are: (1) to determine whether incident ED is more likely to occur among men with low SEF; and (2) to determine whether incident ED varies by SEF after taking into consideration other well-established ED risk factors that are also associated with SEF such as smoking, diabetes, and high blood pressure. We used data from 797 participants in the longitudinal population-based Massachusetts Male Aging Study (baseline 1987-1989, follow-up 1995-1997) who were free of ED at baseline and had complete data on ED and all risk factors. ED was determined by a self-administered questionnaire and its relationship to SEF was assessed using logistic regression. We first analyzed the age-adjusted relationship of education, income, and occupation to incidence of ED. The results show that men with low education (O.R. = 1.46, 95% C.I. = 1.02-2.08) or men in blue-collar occupations (O.R. = 1.68, 95% C.I. = 1.16-2.43) are significantly more likely to develop ED. For the multivariate model, due to multicollinearity among education, income, and occupation, we ran three separate models. After taking into consideration all the other risk factors--age, lifestyle and medical conditions--the effect of occupation remained significant. Men who worked in blue-collar occupations were one and a half times more likely to develop ED compared to men in white-collar occupations (O.R. = 1.55, 95% C.I. = 1.06-2.28).

Modifiable risk factors and erectile dysfunction: can lifestyle changes modify risk?

OBJECTIVES: To prospectively examine whether changes in smoking, heavy alcohol consumption, sedentary lifestyle, and obesity are associated with the risk of erectile dysfunction. METHODS: Data were collected as part of a cohort study of a random sample of men 40 to 70 years old, selected from street listings in the Boston Metropolitan Area, Massachusetts. In-home interviews were completed by 1709 men at baseline in 1987 to 1989 and 1156 men at follow-up in 1995 to 1997 (average follow-up 8.8 years). Analyses included 593 men without erectile dysfunction at baseline, who were free of prostate cancer, and had not been treated for heart disease or diabetes. The incidence of moderate to complete erectile dysfunction was determined by discriminant analysis of responses to a self-administered sexual function questionnaire. RESULTS: Obesity status was associated with erectile dysfunction (P = 0.006), with baseline obesity predicting a higher risk regardless of follow-up weight loss. Physical activity status was associated with erectile dysfunction (P = 0.01), with the highest risk among men who remained sedentary and the lowest among those who remained active or initiated physical activity. Changes in smoking and alcohol consumption were not associated with the incidence of erectile dysfunction (P >0.3). CONCLUSIONS: Midlife changes may be too late to reverse the effects of smoking, obesity, and alcohol consumption on erectile dysfunction. In contrast, physical activity may reduce the risk of erectile dysfunction even if initiated in midlife. Early adoption of healthy lifestyles may be the best approach to reducing the burden of erectile dysfunction on the health and well-being of older men.

Testosterone, sex hormone-binding globulin, and the development of type 2 diabetes in middle-aged men: prospective results from the Massachusetts male aging study.

OBJECTIVE: The objective was to examine prospectively the association between low testosterone and sex hormone-binding globulin (SHBG) levels and the subsequent development of type 2 diabetes in men. RESEARCH DESIGN AND METHODS: Analyses were conducted on the cohort of the Massachusetts Male Aging Study, a population-based random sample of men aged 40-70. Of the 1,709 men enrolled in 1987-1989 (T1), 1,156 were followed up 7-10 years later (T2). Testosterone and SHBG levels at T1 were used to predict new cases of diabetes between T1 and T2. RESULTS: After controlling for potential confounders, diabetes at follow-up was predicted jointly and independently by lower baseline levels of free testosterone and SHBG. The odds ratio for future diabetes was 1.58 for a decrease of 1SD in free testosterone (4 ng/dl) and 1.89 for a 1SD decrease in SHBG (16 nmol/l), both significant at P < 0.02. CONCLUSIONS: Our prospective findings are consistent with previous, mainly cross-sectional reports, suggesting that low levels of testosterone and SHBG play some role in the development of insulin resistance and subsequent type 2 diabetes.