Biomedical subjects

Joseph M Zmuda

Publications and source records attributed to Joseph M Zmuda.

At least 37 records · Page 2Linked to original sources

PubMed2005

Hearing sensitivity and bone mineral density in older adults: the Health, Aging and Body Composition Study.

Bone mineral density (BMD) may be associated with hearing loss in older adults. Demineralization of the cochlear capsule has been associated with hearing loss in those with Paget's disease of the bone and otosclerosis. Osteoporosis may also result in cochlear capsule demineralization. We hypothesized that lower hip BMD and lower heel ultrasound measurements would be associated with hearing loss in a population-based sample of 2,089 older black and white men and women. Bone parameters and hearing function were measured at the fourth clinical follow-up visit. Audiometric threshold testing was used to measure air- and bone-conduction hearing sensitivity. BMD of the hip and its subregions was measured using dual-energy X-ray absorptiometry. Calcaneal bone measurements [broadband ultrasound attenuation (BUA), speed of sound (SOS) and the quantitative ultrasound index (QUI)] were obtained using heel ultrasound. After adjusting for known hearing loss risk factors, no association was found between hearing and any of the bone measurements in whites and black women. In black men, however, lower hip BMD was associated with higher odds of hearing loss; for each standard deviation decrease in total hip BMD, the odds of hearing loss were 1.41 (95% confidence interval 1.08, 1.83), 1.39 (95% CI 1.07, 1.82) for femoral neck BMD and 1.65 (95% CI 1.26, 2.16) for trochanter BMD. Conductive hearing loss was associated with lower heel ultrasound measurements, though only among white men. The results of this study are mixed and inconclusive. Lower BMD of the hip and its subregions was associated with hearing loss among black men, but not among whites or black women. Lower measurements on heel ultrasound were associated with conductive hearing loss, though only among white men. These results suggest that axial and appendicular bone parameters may be modestly associated with hearing loss in older men, but not in women.

Absorptiometry, Photon↗

PubMed2005

Bone mineral density and the risk of incident nonspinal fractures in black and white women.

CONTEXT: Black women have a lower rate of fracture than white women, but whether bone mineral density (BMD) predicts fracture risk as well in black women as it does in white women is not established. OBJECTIVE: To examine the association between BMD and incident nonspinal fractures in older black and white women. DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study of baseline data collected from 1986 through 1990 (7334 white women aged 67-99 years) and from 1996 through 1998 (636 black women aged 65-94 years) at 4 US clinical centers in the Study of Osteoporotic Fractures; mean (SD) follow-up of 6.1 (1.5) years until October 1, 2004. MAIN OUTCOME MEASURES: Incident nonspinal fractures were confirmed by radiograpic report. Total hip and femoral neck BMD and bone mineral content were measured by dual energy x-ray absorptiometry. RESULTS: A total of 58 black women had a combined total of 61 fractures and 1606 white women had a combined total of 1712 fractures. In age-adjusted proportional hazard models, a 1-SD decrease in femoral neck BMD was associated with a 37% increased risk of fracture in black women (relative risk [RR], 1.37; 95% confidence interval [CI], 1.08-1.74) and a 49% increase in fracture in white women (RR, 1.49; 95% CI, 1.40-1.58). Adjustment for body weight and other risk factors for fracture weakened the association between BMD and fracture, especially among black women (multivariable adjusted RR per 1-SD decrease in femoral neck BMD for black vs white women: RR, 1.20 [95% CI, 0.93-1.55] vs RR, 1.42 [95% CI, 1.32-1.52]). The absolute incidence of fracture across the pooled BMD distribution was 30% to 40% lower among black women at every BMD tertile. The lower risk of fracture among black compared with white women was independent of BMD and other risk factors (RR, 0.48; 95% CI, 0.36-0.64). CONCLUSIONS: Decreased total hip and femoral neck BMD is associated with an increased risk of fracture in both older black and white women, but this relationship was largely explained by other risk factors in black women. Black women have a lower fracture risk than white women at every level of BMD. Race-specific normative databases may be appropriate for the densitometric definition of osteoporosis.

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PubMed2005

Estrogen metabolizing polymorphisms and breast cancer risk among older white women.

OBJECTIVE: To investigate breast cancer risk according to metabolizing genes polymorphisms in older women. METHODS: A subset (43.8%) of 4248 older, white women from the Study of Osteoporotic Fractures (SOF) were genotyped for the catechol-O-methyltransferase (COMT) Val108Met polymorphism and the CYP1A1*2C locus. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between genotypes and breast cancer while controlling for potential confounders. RESULTS: During a mean follow up of 12.4 years, 252 women (5.9%) developed breast cancer. The HR (95% CI) for breast cancer was 1.24 (0.87-1.75) for COMT(Val/Met) and 1.35 (0.93-1.97) for COMT(Met/Met). No interactions with lifestyle and reproductive factors were found. The HR associated with the CYP1A1*2C Val allele was 0.80 (0.46, 1.39) with little evidence for interactions with lifestyle or reproductive factors. CONCLUSIONS: Among older white women, neither the COMT Val108/158Met polymorphism nor the CYP1A*2C Val allele plays a major role in breast cancer risk either alone or in combination with lifestyle and reproductive factors.

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PubMed2005

Genetic epidemiology of osteoporosis: past, present, and future.

Research during the past several decades has unequivocally established a role of heredity in the etiology of osteoporosis. Major efforts are currently underway to identify the genes and allelic variants that confer genetic susceptibility to this common and disabling condition. Genome-wide linkage mapping in families, candidate gene association studies in unrelated individuals, and quantitative trait locus mapping in animal models are the primary strategies being used to search for the genetic contributors to osteoporosis. Genome-wide mapping efforts have identified the low-density lipoprotein receptor-related protein 5, bone morphogenetic protein 2, and 15-lipoxygenase as potential susceptibility genes for osteoporosis in the past few years, providing a rich new base for understanding bone biology. Candidate gene association analyses have also provided evidence for a modest role of allelic variants in several additional genes including collagen type Ialpha1, vitamin D receptor, and estrogen receptor-alpha. With the development of a high-density genome-wide polymorphism and haplotype map and continued improvements in high-throughput and cost-effective genotyping technologies, many more genetic contributors to osteoporosis will probably be identified in the near future. The results of this research should facilitate the development of new methods for diagnosing, preventing, and treating the growing clinical and public health problem of osteoporosis.

Animals↗

PubMed2005

Correlates and prevalence of prostatitis in a large community-based cohort of older men.

OBJECTIVES: To describe the prevalence and correlates of self-reported history of prostatitis in terms of lower urinary tract symptoms and associated dissatisfaction in community-dwelling older men. METHODS: We performed a cross-sectional analysis from a prospective cohort study of 5821 men aged 65 years and older recruited from six clinical centers. RESULTS: Overall, 1439 men (25%) self-reported a history of prostatitis. Men with a history of prostatitis were more likely to self-report a history of prostate cancer (26% versus 7%; P < 0.0001) and a history of benign prostatic hyperplasia (83% versus 38%; P < 0.0001) within a lifetime compared with men without a history of prostatitis. Men with a history of prostatitis also had a greater mean American Urological Association symptom score (mean +/- SD, 10.1 +/- 7.1 versus 7.7 +/- 5.9; P < 0.0001) than men without a history of prostatitis. Also, a greater percentage of men with a history of prostatitis reported being dissatisfied with their present urinary condition than did men without a history of prostatitis (21% versus 11%; P < 0.0001). We found positive associations for a history of prostatitis with a history of benign prostatic hyperplasia (odds ratio 8.0, 95% confidence interval 6.8 to 9.5), a history of prostate cancer (odds ratio 5.4, 95% confidence interval 4.4 to 6.6), and dissatisfaction with current urinary condition (odds ratio 1.2, 95% confidence interval 1.01 to 1.5). CONCLUSIONS: A self-reported history of prostatitis is common in older men and was associated with self-reported prostate cancer and benign prostatic hyperplasia and increased severity of lower urinary tract symptoms and associated dissatisfaction. Because of the potential detection bias, recall bias, and the cross-sectional nature of the study, limiting causal inference, the associations among these urologic conditions require additional study.

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PubMed2005

Race and sex differences in age-related hearing loss: the Health, Aging and Body Composition Study.

OBJECTIVES: To determine the prevalence of and risk factors for hearing loss in a sample of 2,052 older adults (aged 73-84; 46.9% male, 37.3% black) enrolled in the Health, Aging and Body Composition (Health ABC) Study. DESIGN: Cross-sectional analysis of a longitudinal cohort study. SETTING: Pittsburgh, Pennsylvania, and Memphis, Tennessee, areas. PARTICIPANTS: Random sample of Medicare beneficiary subjects enrolled in the Health ABC program from 1997 to 1998. They included 2,052 individuals: 660 white men (32.2%), 631 white women (30.8%), 310 black men (15.1%), and 451 black women (22.0%). Participants ranged in age from 73 to 84, with a mean age of 77.5. MEASUREMENTS: Hearing sensitivity was measured using pure-tone threshold testing. Hearing loss was defined based on two averages of hearing thresholds: 500, 1,000, and 2,000 Hz greater than 25-decibel (dB) hearing level (HL) (hearing loss); and 2,000, 4,000, and 8,000 Hz greater than 40-dB HL (high-frequency hearing loss). Potential hearing loss correlates, including demographics, medical history, ototoxic medication use, occupational noise exposure, and lifestyle factors, were collected via questionnaire. RESULTS: The prevalence of hearing loss was 59.9%; the prevalence of high-frequency hearing loss was 76.9%. Hearing loss was most common in white men, followed by white women, black men, and black women. Older age, white race, diabetes mellitus, cerebrovascular disease, smoking, poorer cognitive status, occupational noise exposure, and ear surgery were associated with hearing loss after multivariable adjustment. Race- and sex-specific risk factors included higher blood pressure and occupational noise exposure (white men), poorer cognitive status and smoking (black women), and low total hip bone mineral density (black men). Possible protective factors included salicylate use (overall sample, black men) and moderate alcohol intake (black women). CONCLUSION: Hearing loss was extremely common in this population. Because many of the identified hearing loss risk factors are modifiable, some of the burden associated with hearing loss in older people should be preventable.

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PubMed2005

Longitudinal study of changes in hip bone mineral density in Caucasian and African-American women.

OBJECTIVES: To determine whether changes in hip bone mineral density (BMD) differ in Caucasian and African American women. DESIGN: Longitudinal study of changes in hip BMD. SETTING: Four U.S. clinical centers. PARTICIPANTS: Six thousand seven Caucasian (mean age 73) and 482 African-American (mean age 75) women enrolled in the Study of Osteoporotic Fractures. MEASUREMENTS: Total hip and femoral neck BMD were measured an average of 3.5 years apart (Caucasian) and 2.0 years apart (African American). Annual absolute and percentage changes in BMD and bone mineral apparent density (BMAD) were calculated. RESULTS: The multivariate adjusted annual percentage change in BMD was greater in Caucasian than African-American women at the total hip (-0.574%/y vs -0.334%/y) and femoral neck (-0.515%/y vs -0.203%/y) (both, P<.001). Similar findings were observed for BMAD. The average annualized rate of BMD loss was twice as high in women aged 75 and older as in women younger than 75 in both ethnic groups. The annual percentage loss in femoral neck BMD in nonusers versus hormone therapy users was (-0.57% vs -0.22%) in Caucasians and (-0.35% vs 0.64%) in African Americans (interaction P=.03). CONCLUSION: The average rate of hip BMD loss is approximately twice as great in Caucasian as African-American women and increases with age in both groups. The hormonal and biochemical factors that contribute to ethnic differences and the increase in bone loss with advancing age need to be identified.

Absorptiometry, Photon↗

PubMed2005

Ethnic differences in the frequency and circumstances of falling in older community-dwelling women.

OBJECTIVES: To examine ethnic differences in fall rates and fall circumstances in older community-dwelling Caucasian and African-American women. DESIGN: Prospective analysis of incident falls and a nested retrospective analysis of fall circumstances over 5.7 years. SETTING: Monongahela Valley, Pennsylvania. PARTICIPANTS: A total of 1,821 Caucasian and African-American women (mean age+/-standard deviation 76+/-5) enrolled in the Study of Osteoporotic Fractures and participating in 1993/94. Circumstances of 338 falls were collected on a subsample of 197 women who fell. MEASUREMENTS: Fall rates and fall circumstances. RESULTS: Women reported 4,547 falls in 9,508 person-years, averaging 0.48 falls per woman annually (95% confidence interval (CI)=0.43-0.53). Age-adjusted fall rates were nonsignificantly higher in Caucasians than African Americans (relative risk (RR)=1.30, 95% CI=0.93-1.83%). In women younger than 75, fall rates were similar in Caucasians and African Americans (RR=1.17, P=.46). In women aged 75 and older, fall rates were 50% higher in Caucasians than in African Americans (RR=1.50, 95% CI=0.90-2.49), although this difference was not significant (P=.12). Fall circumstances differed by ethnicity. Caucasian women were significantly more likely than African Americans to fall outdoors versus indoors (odds ratio (OR)=1.6, 95% CI =1.0-2.7) and laterally versus forward (OR=2.0, 95% CI =1.1-3.4) but less likely to fall on the hand/wrist (OR=0.6, 95% CI =0.3-1.0). Ninety-eight percent of individuals falling on their hand/wrist reported that they extended their hand to attempt to break their fall. CONCLUSION: Although the circumstances of falling differed for older Caucasian and African-American women, there were no differences in the frequencies of falling. These findings suggest that ethnic differences in fracture risk in older women may be due in part to the different ways in which older Caucasian and African-American women fall, rather than how often they fall. More information will be needed on fall circumstances to determine whether interventions need to be tailored by ethnic group.

Accidental Falls↗

PubMed2004

Androgen receptor CAG repeat polymorphism is associated with fat-free mass in men.

The human androgen receptor (AR) gene contains a CAG (glutamine) repeat polymorphism in exon 1 that is inversely associated with transcriptional activity of the AR. We studied the association of AR CAG repeat length, fat-free mass (FFM), and testosterone in two independent cohorts: 294 Caucasian men, aged 55-93 yr, from the Study of Osteoporotic Risk in Men (STORM), and 202 Caucasian volunteers (112 men and 90 women), aged 19-90 yr, from the Baltimore Longitudinal Study of Aging (BLSA). Subjects were genotyped to determine the number of AR CAG repeats and grouped as carrying either < 22 or > or =22 repeats. Whole body soft tissue composition was measured by dual-energy X-ray absorptiometry. Men with greater CAG repeat number exhibited significantly greater total FFM than those with fewer CAG repeats in both cohorts (STORM: 59.2 +/- 0.3 vs. 58.0 +/- 0.4 kg, P = 0.02; BLSA: 57.2 +/- 1.1 vs. 53.8 +/- 1.1 kg, P = 0.04). Similar results were observed for total FFM normalized to height. No differences were seen in women in the BLSA cohort. In the BLSA cohort, serum testosterone levels were higher in subjects with greater repeat number (P = 0.003). This same pattern approached significance in the STORM cohort (P = 0.07). In conclusion, the androgen receptor CAG repeat polymorphism is associated with FFM in men in two independent cohorts. Additional studies are needed to confirm this observation and to clarify the mechanisms involved.

Adipose Tissue↗

PubMed2004

Association of the G-174C variant in the interleukin-6 promoter region with bone loss and fracture risk in older women.

UNLABELLED: We analyzed the association between the IL-6 G-174C polymorphism and osteoporosis phenotypes in 3376 older women. Women with the C/C genotype had a significantly slower rate of decline in hip BMD and a 33% lower risk of wrist fracture than women with the G/G genotype. Variation at the IL-6 locus may contribute to the genetic susceptibility to bone fragility. INTRODUCTION: Interleukin 6 (IL-6) promotes osteoclast formation and bone resorption. The C allele of the G-174C polymorphism in the IL-6 promoter region has been related to lower gene transcription and plasma IL-6 levels. MATERIALS AND METHODS: In this study, we evaluated the relationship between the IL-6 G-174C polymorphism and BMD, the rate of decline in BMD, and the risk of fracture in 3376 women 65 years of age and older participating in the Study of Osteoporotic Fractures. BMD was measured at the distal and proximal radius using single photon absorptiometry and at the hip using DXA. Hip BMD was measured again an average of 3.5 years later. Incident fractures over an average of 10.8 years of follow-up were confirmed by physician adjudication of radiology reports. RESULTS: Distal and proximal radius BMD was lowest among women with the G/G genotype, intermediate in the heterozygotes, and highest in women with the C/C genotype (p = 0.016 and p = 0.049, respectively), although the differences between the genotypes were small. While there were no differences by genotype with initial hip BMD, women with the C/C genotype experienced a slower rate of decline in total hip and femoral neck BMD compared with women with the G/G genotype (p = 0.004 and p = 0.029, respectively). Women with the C/C genotype also had 33% lower risk of wrist fracture compared with women with the G/G genotype, independent of age, body mass index, estrogen use, and study center (RR, 0.67; 95% CI, 0.45, 1.00; p = 0.048), whereas heterozygous women had a more intermediate risk (RR, 0.85; 95% CI, 0.65, 1.12; p = 0.256). No association was found between genotype and risk of hip or all non-spine fractures. CONCLUSIONS: These results suggest that the IL-6 G-174C promoter polymorphism may be a genetic marker for bone loss and wrist fracture among older women.

Aged↗

PubMed2004

Diabetes is associated independently of body composition with BMD and bone volume in older white and black men and women: The Health, Aging, and Body Composition Study.

UNLABELLED: The association between type 2 diabetes, BMD, and bone volume was examined to determine the effect of lean and fat mass and fasting insulin in the Health, Aging, and Body Composition Study, which included white and black well-functioning men and women 70-79 years of age (N = 2979). Diabetes predicted higher hip, whole body, and volumetric spine BMD, and lower spine bone volume, independent of body composition and fasting insulin. INTRODUCTION: The purpose of this study was to determine if the association between type 2 diabetes and higher BMD observed in older white women is seen in elderly white men and blacks and to evaluate if higher BMD in diabetic individuals is accounted for by lean mass, fat mass, or fasting insulin differences. MATERIALS AND METHODS: In the Health, Aging, and Body Composition Study, which included white and black well-functioning men and women 70-79 years of age (N = 2979), 19% of participants had diabetes at baseline. Of those with diabetes, 57% were men, and 62% were black. Multivariate linear regression models examined independent effects of diabetes, lean mass, fat mass, visceral fat, and fasting insulin on BMD and bone volume while adjusting for relevant covariates. RESULTS AND CONCLUSIONS: Fasting insulin, visceral fat, and volumetric spine BMD, assessed by CT, and lean mass, fat mass, and total hip and whole body BMD, assessed by DXA, were higher (p < or = 0.05 for all) for those with diabetes. Hip BMD was higher in white men (0.99 +/- 0.14 versus 0.93 +/- 0.14 g/cm2, p < 0.001), black men (1.06 +/- 0.17 versus 1.00 +/- 0.15 g/cm2, p < 0.001), white women (0.83 +/- 0.13 versus 0.76 +/- 0.13 g/cm2, p < 0.001), and black women (0.90 +/- 0.15 versus 0.85 +/- 0.15 g/cm2, p < 0.001) with diabetes compared with those without diabetes, although the relationship was attenuated by body composition. In multiple regression models, diabetes was an independent predictor of higher hip, whole body, and volumetric spine BMD in all participants (p < or = 0.001), but lower spine volume (p = 0.01) and higher hip BMD for each race-gender group (p < or = 0.01). Type 2 diabetes was associated with a 4-5% higher total hip BMD in all race-gender groups of elderly adults, independent of body composition and fasting insulin levels.

Aged↗

PubMed2004

Hearing sensitivity and the risk of incident falls and fracture in older women: the study of osteoporotic fractures.

PURPOSE: To determine if age-related hearing loss may be related to bone health. Decreased vestibular function has been associated with hearing loss. We hypothesized that hearing loss would be related to an increased risk of falling and osteoporotic fracture in 6480 women aged 65 years or older enrolled in the Study of Osteoporotic Fractures. We further hypothesized that decreased bone mineral density would be associated with hearing loss. METHODS: Hearing sensitivity was ascertained via screening audiometry, and was classified as normal, mild loss, or significant loss. Incident non-spine fractures and falls were ascertained every 4 months for an average 6.7 years and 3 years, respectively. RESULTS: The age-adjusted annual fall rate did not differ significantly by hearing category, nor did the risk of incident fracture. Adjustment for confounding factors had no effect on our results. Age- and BMI-adjusted mean calcaneal bone mineral density (g/cm2) was 0.380 in the normal hearing group, 0.375 in the mild loss group, and 0.371 in the significant loss group (p = 0.02). There were no significant differences in total hip bone mineral density across hearing categories. CONCLUSIONS: Our results do not support the hypothesis that hearing loss is a risk factor for fracture or falls [corrected]

Accidental Falls↗

PubMed2004

Ciliary neurotrophic factor (CNTF) genotype and body composition.

Exogenous ciliary neurotrophic factor (CNTF) administration causes significant weight loss in both humans and animal models, but the effects of endogenous CNTF and the CNTF null allele on body composition are not fully understood. A recent study in a European cohort demonstrated a significantly higher body weight and body mass index (BMI) in older males homozygous for the CNTF null allele (A/A genotype). We sought to replicate these findings in three cohorts: the Baltimore Longitudinal Study on Aging (BLSA) consisting of 422 adult men and women (19-90 years); the Study of Osteoporotic Risk in Men (STORM) consisting of 333 older men (50-84 years); and a third sample obtained by combining older males aged 59-73 years from the BLSA and STORM cohorts (n=286). In contrast to the European study, we were unable to detect a significant association between CNTF genotype and body weight in the BLSA (P=0.49), the STORM (P=0.28), or the combined samples (P=0.72). There was also no significant association observed between CNTF genotype and BMI in the BLSA (P=0.59), the STORM (P=0.34) or the combined (P=0.56) samples. In addition, we were unable to detect a significant association between CNTF genotype and total body fat (P=0.95) or fat-free mass (P=0.86) in the BLSA cohort. Our results do not support an effect of the CNTF null allele on body composition, contrary to previous findings.

Adult↗

PubMed2004

Vitamin D receptor genotype is associated with fat-free mass and sarcopenia in elderly men.

We investigated the association of vitamin D receptor (VDR) genotype with fat-free mass (FFM) in a cohort of 302 older (aged 58-93 years) Caucasian men who underwent body composition analysis by dual-energy X-ray absorptiometry, and completed questionnaires addressing comorbidities, physical activity, and dietary intake. All participants were genotyped for a VDR translation start site (FokI) polymorphism [FF (37.7%), Ff (48.4%), and ff (13.9%)] and the previously studied BsmI polymorphism [BB (24.9%), Bb (37.7%), and bb (37.4%)]. The BsmI polymorphism was not associated with FFM in any analysis; however, the FokI polymorphism was significantly associated with total FFM, appendicular FFM, and relative (kg/m(2)) appendicular FFM (all p <.05), with the FF group demonstrating significantly lower FFM than the Ff and ff groups (e.g., total FFM: FF = 57.6 +/- 0.4, Ff = 59.4 +/- 0.4, ff = 59.4 +/- 0.7 kg; p <.02). Age-adjusted logistic regression revealed a 2.17-fold higher risk for sarcopenia (defined previously as appendicular FFM <7.26 kg/m(2)) in FF homozygotes (95% CI [confidence interval] = 1.19-3.85; p =.03) compared to men with one or more f alleles. The VDR translation start site (FokI) polymorphism is significantly associated with FFM and sarcopenia in this cohort of older Caucasian men.

Aged↗

PubMed2004

Depressive symptoms and bone mineral density in older men.

Most studies examining the relation between depression and bone mineral density (BMD) have been limited to psychiatric patients or to community-dwelling, older women. We conducted a cross-sectional and prospective cohort study to determine whether depressive symptoms are associated with low BMD in community-dwelling, older men. We recruited 515 men 50 years of age or older from population-based listings of age-eligible men. Participants completed the Geriatric Depression Scale (short form) and were considered depressed if they scored 6 or more out of 15 possible points. BMD was measured in the spine and hip using dual energy x-ray absorptiometry in all participants, and again an average of 3.6 years later in a random subset of 100 participants. The prevalence of depressive symptoms (GDS = 6) was 3.1% (16 of 515). We found no difference in mean BMD or mean percent change in BMD per year of the hip and lumbar spine in men who had 6 or more depressive symptoms compared with men who reported 5 or fewer symptoms of depression. These findings suggest that depressive symptoms are not associated with BMD in community-dwelling, older men.

Absorptiometry, Photon↗

PubMed2003

Bone mineral density and prevalent vertebral fractures in men and women.

To test the hypothesis that the association between bone mineral density (BMD) and estimated volumetric BMD and prevalent vertebral fractures differs in men and women, we studied 317 Caucasian men and 2,067 Caucasian women (average age 73 years). A total of 43 (14%) men and 386 (19%) women had a vertebral fracture identified on lateral spine radiographs using vertebral morphometry. Hip and spine areal BMD was about 1/3 standard deviation lower among men and women with a vertebral fracture. A 0.10 g/cm(2) decrease in areal BMD was associated with 30-40% increased odds of having a fracture in men and 60-70% increased likelihood in women. Low bone mineral apparent density (BMAD) was also associated with 40-50% increased odds of a vertebral fracture in both genders. The probability of a man having a fracture was observed at higher absolute areal BMD values than observed for women (P=values for interaction of BMD x gender: trochanter, P=0.05; femoral neck, P=0.10; total hip, P=0.09). In contrast, the probability of fracture was similar in men and women across the range of estimated volumetric BMD (BMAD). In conclusion, low BMD and low BMAD are associated with increased odds of vertebral fracture in both men and women. Measures of bone mass that partially correct for gender differences in bone size may yield universal estimates of fracture risk. Prospective studies are needed to confirm this observation.

Aged↗

PubMed2003

Androgen receptor CAG repeat polymorphism is associated with cognitive function in older men.

BACKGROUND: Androgen receptors are located throughout the brain, especially in regions involved with learning and memory. Different lengths of a CAG (glutamine) repeat polymorphism in exon 1 of the androgen receptor gene may influence androgen action, with longer repeat lengths conferring decreased androgen sensitivity. METHODS: We sought to determine if this CAG polymorphism was associated with cognition in older men. RESULTS: Among 301 community-dwelling white men (mean age, 73.0 +/- 7.1), greater CAG repeat length was associated with lower scores on three cognitive tests (p <.05 for all). In addition, 12 participants (9.8%) had cognitive impairment in the low tertile of CAG repeat length whereas 29 (16.3%) had cognitive impairment in the two higher tertiles (odds ratio = 1.8; 95% confidence interval =.9-3.7). CONCLUSIONS: Research should be directed at identifying the mechanism for this association and to determine if treatment with testosterone prevents cognitive decline.

Aged↗

PubMed2003

Vitamin D receptor and aromatase gene interaction and bone mass in older African-American women.

Aromatization of androgens by the CYP19 gene product, aromatase, is the major source of endogenous estrogen in postmenopausal women. We determined whether an Arg(264)Cys polymorphism in the CYP19 gene is associated with bone mineral density (BMD) and bone loss in older women. Because vitamin D regulates CYP19 gene expression, we also tested for an interaction with a translation start site polymorphism in the vitamin D receptor (VDR) gene. Hip BMD was measured twice, an average of 1.9 years apart, in 100 African-American women aged > or =65 years. Neither polymorphism alone was significantly associated with BMD or bone loss. BMD measurements in women with the less frequent allele at both loci were 0.5 to 1.3 SD lower than in women with neither or only a single rare allele (P <.001 for interaction). These women also experienced more rapid hip bone loss than other women (P <.05 for interaction). We conclude that VDR and CYP19 gene polymorphisms may jointly influence bone mass and the rate of bone loss in older African-American women.

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