Sleep duration and bone health measures in older men.

The associations between objective measures of sleep duration and bone outcomes in older men are unknown. No consistent, significant association was identified between sleep duration and bone mineral density (BMD) in the current analysis. However, future research should determine if vitamin D status modifies this relationship. INTRODUCTION: Prior studies, predominantly in women, reported that long and short self-reported sleep duration are associated with lower BMD. Associations between actigraphy-determined sleep duration and BMD or bone turnover markers (BTMs) in older men are unknown. METHODS: Men in The Osteoporotic Fractures in Men (MrOS) Study with wrist actigraphy and concurrent BMD assessment but without comorbidities affecting bone health were included. Sleep duration was considered as a continuous (N = 1926) and dichotomized variable where men were classified as getting the recommended (7-8 h/night; N = 478) or short (< 6 h/night; N = 577) sleep. The cross-sectional association between BMD, BTMs, and sleep duration was examined using a t test or linear regression, where appropriate, in unadjusted and adjusted models. RESULTS: There were no clinically or statistically significant differences in BMD at the L-spine, total hip, or femoral neck between men getting the recommended vs. short sleep duration, using actigraphy or self-reported sleep duration (all p ≥ 0.07). When sleep duration was considered as a continuous variable, femoral neck BMD was higher in men with longer self-reported sleep duration (ß = 0.006 ±0.003, p = 0.02), but this was not significant after further adjustment. In men with low 25OHD (< 20 ng/mL), longer actigraphy-determined sleep duration was associated with higher total hip BMD (ß = 0.016 ± 0.008; p = 0.04). Sleep duration and BTMs were not associated. CONCLUSION: Sleep duration was not associated with hip or L-spine BMD or BTMs in older men. Future research should determine if vitamin D status or other factors modify this relationship.

Heightened sleep propensity: a novel and high-risk sleep health phenotype in older adults.

OBJECTIVES: To reveal sleep health phenotypes in older adults and examine their associations with time to 5-year all-cause and cardiovascular mortality. DESIGN: Prospective longitudinal cohorts. SETTING: The Study of Osteoporotic Fractures and Outcomes of Sleep Disorders in Older Men Study. PARTICIPANTS: N = 1722 men and women aged ≥65 years matched 1:1 on sociodemographic and clinical measures. MEASUREMENTS: Self-reported habitual sleep health characteristics (satisfaction, daytime sleepiness, timing, efficiency, and duration) measured at an initial visit and longitudinal follow-up for mortality. RESULTS: Latent class analysis revealed 3 sleep health phenotypes: (1) heightened sleep propensity (HSP; medium to long duration, high sleepiness, high efficiency/satisfaction; n = 322), (2) average sleep (AS; medium duration, average efficiency, high satisfaction, low sleepiness; n = 1,109), and (3) insomnia with short sleep (ISS; short to medium duration, low efficiency/satisfaction, moderate sleepiness; n = 291). Phenotype predicted time to all-cause mortality (χ2 = 9.4, P = .01), with HSP conferring greater risk than AS (hazard ratio [95% confidence interval] = 1.48 [1.15-1.92]) or ISS (1.52 [1.07-2.17]), despite ISS reporting the poorest mental and physical health. Although sex did not formally moderate the relationship between phenotype and mortality, subgroup analyses indicated that these findings were driven primarily by women. Phenotype did not predict cardiovascular mortality. CONCLUSIONS: These analyses support the utility of examining multidimensional sleep health profiles by suggesting that the combination of long sleep, high efficiency/satisfaction, and daytime sleepiness-previously identified as independent risk factors-may be components of a single high-risk sleep phenotype, HSP. Further investigation of sex differences and the mechanisms underlying mortality risk associated with HSP is warranted.

Association between objective sleep duration and bone mineral density in older postmenopausal women from the Study of Osteoporotic Fractures (SOF).

Methodological limitations preclude determination of the association between sleep duration and bone mineral density (BMD) from existing literature. This was the first study to use objective sleep duration to determine its association with BMD. Nocturnal sleep duration, assessed objectively (actigraphy) or subjectively (questionnaire), was not independently associated with BMD in postmenopausal women. INTRODUCTION: Both long and short self-reported sleep durations are associated with low bone mineral density (BMD) in men and women. The association between sleep duration measured by actigraphy and BMD in postmenopausal women is unknown. METHODS: The Study of Osteoporotic Fractures (SOF) ancillary sleep study was used to determine the association between sleep duration and BMD at the total hip and femoral neck in postmenopausal women ≥ 75 years old. Sleep duration was assessed by wrist actigraphy (average 4 nights) and questionnaire. BMD was compared between postmenopausal women with short (< 6 h/night) vs. NIH-recommended (7-8 h/night) sleep durations. Data were analyzed using a 2-sample t test (unadjusted) and multivariate regression model (adjusted). Simple linear regression was used to estimate the difference in BMD per additional hour of sleep when sleep duration was considered as a continuous, rather than dichotomized, variable. RESULTS: Total hip BMD was higher in women with actigraphically assessed shorter sleep duration in unadjusted models only. No clinically or statistically significant differences in total hip or femoral neck BMD were observed according to nocturnal sleep duration after adjusting for body mass index (BMI) in dichotomized (N = 874) or continuous (N = 1624) sleep duration models or when subjective sleep duration was used. When sleep duration included daytime naps, longer sleep duration was associated with lower total hip BMD (ß = - 0.005, p = 0.04). CONCLUSIONS: Nocturnal sleep duration, whether assessed objectively (actigraphy) or subjectively (questionnaire), was not independently associated with BMD in older postmenopausal women.

Rare human nicotinic acetylcholine receptor α4 subunit (CHRNA4) variants affect expression and function of high-affinity nicotinic acetylcholine receptors.

Nicotine, the primary psychoactive component in tobacco smoke, produces its behavioral effects through interactions with neuronal nicotinic acetylcholine receptors (nAChRs). α4ß2 nAChRs are the most abundant in mammalian brain, and converging evidence shows that this subtype mediates the rewarding and reinforcing effects of nicotine. A number of rare variants in the CHRNA4 gene that encode the α4 nAChR subunit have been identified in human subjects and appear to be underrepresented in a cohort of smokers. We compared three of these variants (α4R336C, α4P451L, and α4R487Q) to the common variant to determine their effects on α4ß2 nAChR pharmacology. We examined [(3)H]epibatidine binding, interacting proteins, and phosphorylation of the α4 nAChR subunit with liquid chromatography and tandem mass spectrometry (LC-MS/MS) in HEK 293 cells and voltage-clamp electrophysiology in Xenopus laevis oocytes. We observed significant effects of the α4 variants on nAChR expression, subcellular distribution, and sensitivity to nicotine-induced receptor upregulation. Proteomic analysis of immunopurified α4ß2 nAChRs incorporating the rare variants identified considerable differences in the intracellular interactomes due to these single amino acid substitutions. Electrophysiological characterization in X. laevis oocytes revealed alterations in the functional parameters of activation by nAChR agonists conferred by these α4 rare variants, as well as shifts in receptor function after incubation with nicotine. Taken together, these experiments suggest that genetic variation at CHRNA4 alters the assembly and expression of human α4ß2 nAChRs, resulting in receptors that are more sensitive to nicotine exposure than those assembled with the common α4 variant. The changes in nAChR pharmacology could contribute to differences in responses to smoked nicotine in individuals harboring these rare variants.

The association between sleep patterns and obesity in older adults.

BACKGROUND: Reduced sleep duration has been increasingly reported to predict obesity. However, timing and regularity of sleep may also be important. In this study, the cross-sectional association between objectively measured sleep patterns and obesity was assessed in two large cohorts of older individuals. METHODS: Wrist actigraphy was performed in 3053 men (mean age: 76.4 years) participating in the Osteoporotic Fractures in Men Study and 2985 women (mean age: 83.5 years) participating in the Study of Osteoporotic Fractures. Timing and regularity of sleep patterns were assessed across nights, as well as daytime napping. RESULTS: Greater night-to-night variability in sleep duration and daytime napping were associated with obesity independent of mean nocturnal sleep duration in both men and women. Each 1 h increase in the standard deviation of nocturnal sleep duration increased the odds of obesity 1.63-fold (95% confidence interval: 1.31-2.02) among men and 1.22-fold (95% confidence interval: 1.01-1.47) among women. Each 1 h increase in napping increased the odds of obesity 1.23-fold (95% confidence interval: 1.12-1.37) in men and 1.29-fold (95% confidence interval: 1.17-1.41) in women. In contrast, associations between later sleep timing and night-to-night variability in sleep timing with obesity were less consistent. CONCLUSIONS: In both older men and women, variability in nightly sleep duration and daytime napping were associated with obesity, independent of mean sleep duration. These findings suggest that characteristics of sleep beyond mean sleep duration may have a role in weight homeostasis, highlighting the complex relationship between sleep and metabolism.

Depressive symptoms and rates of bone loss at the hip in older men.

UNLABELLED: In this prospective cohort study, depressive symptoms were associated with higher rates of bone loss in older men. Poorer performance on physical function tests partly explained the association between depressive symptoms and bone loss, suggesting that efforts to increase exercise and improve physical performance in depressed men may be beneficial. INTRODUCTION: The aim of this study was to ascertain whether depressive symptoms are associated with increased rates of bone loss at the hip in older men. METHODS: A population-based prospective cohort study of 2,464 community-dwelling men, aged 68 and older, enrolled in the Osteoporosis in Men Sleep Ancillary Study had depressive symptoms assessed by the Geriatric Depression Scale (GDS). Subjects were categorized as depressed if GDS ≥6 at the initial examination. Bone mineral density (BMD) at the hip was measured using dual-energy X-ray absorptiometry at the initial and follow-up examination (average 3.4 years between exams). Use of antidepressant medications was assessed by interview and verified from medication containers at the two examinations. A computerized dictionary was used to categorize type of medication. RESULTS: In a base model adjusted for age, race/ethnicity, and clinic site, the mean total hip BMD decreased 0.70 %/year in 136 men with a GDS score of ≥6 compared to 0.39 %/year in 2,328 men with a GDS score of <6 (p = 0.001). Walking speed and timed chair stand partly explained the association between depressive symptoms and rates of bone loss. CONCLUSION: Depression, as defined by a score of 6 or greater on the Geriatric Depression Scale, is associated with an increased rate of bone loss at the hip in this cohort of older men. Adjustment for walking speed and timed chair stand attenuated the strength of the association, suggesting that differences in physical functioning do partially explain the observed association.

The association between sleep duration and obesity in older adults.

BACKGROUND: Reduced sleep has been reported to predict obesity in children and young adults. However, studies based on self-report have been unable to identify an association in older populations. In this study, the cross-sectional associations between sleep duration measured objectively and measures of weight and body composition were assessed in two cohorts of older adults. METHODS: Wrist actigraphy was performed for a mean (s.d.) of 5.2 (0.9) nights in 3055 men (age: 67-96 years) participating in the Osteoporotic Fractures in Men Study (MrOS) and 4.1 (0.8) nights in 3052 women (age: 70-99 years) participating in the Study of Osteoporotic Fractures (SOF). A subgroup of 2862 men and 455 women also underwent polysomnography to measure sleep apnea severity. RESULTS: Compared to those sleeping an average of 7-8 h per night, and after adjusting for multiple risk factors and medical conditions, a sleep duration of less than 5 h was associated with a body mass index (BMI) that was on average 2.5 kg/m(2) (95% confidence interval (CI): 2.0-2.9) greater in men and 1.8 kg/m(2) (95% CI: 1.1-2.4) greater in women. The odds of obesity (BMI >or= 30 kg/m(2)) was 3.7-fold greater (95% CI: 2.7-5.0) in men and 2.3-fold greater in women (95% CI: 1.6-3.1) who slept less than 5 h. Short sleep was also associated with central body fat distribution and increased percent body fat. These associations persisted after adjusting for sleep apnea, insomnia and daytime sleepiness. CONCLUSIONS: In older men and women, actigraphy-ascertained reduced sleep durations are strongly associated with greater adiposity.

Preclinical cognitive decline and subsequent sleep disturbance in older women.

OBJECTIVE: To determine whether longitudinal cognitive decline is associated with increased risk of sleep disturbance in older, nondemented, community-dwelling women. METHODS: We studied 2,474 women (mean age 68.9 years) who were part of a prospective study started in 1986; women with baseline or follow-up evidence of possible dementia were excluded. Cognitive data were gathered over 15 years for modified Mini-Mental State Examination (mMMSE) and 13 years for Trails B; cognitive decline was defined as declining >1.5 SDs on the mMMSE (> or =3 points) or Trails B (>92 seconds). Sleep disturbance was measured objectively using actigraphy (Sleepwatch-O, Ambulatory Monitoring) at the 15-year follow-up visit; measures included total sleep hours, sleep efficiency, sleep latency, napping, and time awake after sleep onset (WASO). RESULTS: During follow-up, 11% of women declined on mMMSE and 15% on Trails B. Cognitive decliners were more likely than non-decliners to experience sleep disturbance at follow-up on most measures. For women who declined on mMMSE, adjusted ORs (aOR) (95% CI) were 1.71 (1.24, 2.37) for sleep efficiency <70%, 1.57 (1.12, 2.21) for sleep latency > or =1 hour, and 1.43 (1.07, 1.92) for WASO > or =90 minutes. Results were similar for women who declined on Trails B; in addition, these women were more likely to nap >2 hours per day (aOR: 1.73; 95% CI: 1.28, 2.33). Cognitive decline on either test was not associated with total sleep time. CONCLUSIONS: Cognitive decline is associated with sleep disturbance in nondemented community-dwelling elderly women.

Demographic factors associated with the diet quality of older US men: baseline data from the Osteoporotic Fractures in Men (MrOS) study.

OBJECTIVE: Throughout the world, the proportion of the male population aged 65 years and older is increasing. Yet, we have limited information regarding diet quality and predictors of diet quality in this segment of the population. The objectives of the current analyses are to describe the diet quality of a cohort of men >65 years of age, and identify lifestyle factors associated with poor diet quality. METHODS: We present a cross-sectional analysis of the diet quality of 5928 men, aged 65-100 years, who are participants in the Osteoporotic Fractures in Men (MrOS) cohort study. Dietary intake was determined using a modified Block 98 food-frequency questionnaire. Diet quality was calculated using the previously validated Diet Quality Index-Revised (DQI-R). Univariate and multivariate modelling was used to estimate the variance in diet quality predicted by a number of sociodemographic factors, including age, race/ethnicity, body mass index (BMI), marital status, education, smoking status, physical activity, self-perceived health and nutritional supplement use. RESULTS: Overall, we found that in this geographically diverse group of older men, diet quality was low, with a mean modified DQI-R for the entire study population of 62.5 (standard deviation 13.1) out of an ideal of 100. Further, younger age, very low total calorie intake (< or = 1187 kcal day- 1), higher BMI, residence in a North or Southeast community, being of African-American or Hispanic race, being less educated, not using dietary supplements and smoking were each significant independent predictors of a poorer diet. CONCLUSION: These data may prove useful in both understanding the dietary intake of older US men as it relates to published dietary guidelines, and for targeting future dietary intervention programmes.

Tumor necrosis factor-alpha polymorphism, bone strength phenotypes, and the risk of fracture in older women.

TNFalpha is a proinflammatory cytokine that promotes osteoclastic bone resorption. We evaluated the association between a G-308A polymorphism (rs1800629) at the TNFA locus and osteoporosis phenotypes in 4306 older women participating in the Study of Osteoporotic Fractures. Femoral neck bone mineral density (BMD) and structural geometry were measured using dual-energy x-ray absorptiometry and hip structural analysis. Incident fractures were confirmed by physician adjudication of radiology reports. Despite similar femoral neck BMD, women with the A/A genotype had greater subperiosteal width (P = 0.01) and endocortical diameter (P = 0.03) than those with the G/G genotype. The net result of these structural differences was that there was a greater distribution of bone mass away from the neutral axis of the femoral neck in women with the A/A genotype, resulting in greater indices of bone bending strength (cross-sectional moment of inertia: P = 0.004; section modulus: P = 0.003). Among 376 incident hip fractures during 12.1 yr of follow-up, a 22% decrease in the risk of hip fracture was seen per copy of the A allele (relative risk 0.78; 95% confidence interval 0.63, 0.96), which was not influenced by adjustments for potential confounding factors, BMD, or bone strength indices. The G-308A polymorphism was not associated with a reduced risk of other fractures. These results suggest a potential role of genetic variation in TNFalpha in the etiology of osteoporosis.

Antiepileptic drug use increases rates of bone loss in older women: a prospective study.

OBJECTIVE: To test the hypothesis that older women with antiepileptic drug (AED) use have increased rates of bone loss. METHODS: AED use was ascertained and calcaneal and hip bone mineral density (BMD) measured in a cohort of 9,704 elderly community-dwelling women enrolled in the Study of Osteoporotic Fractures, and they were followed prospectively for changes in BMD. Current use of AED was assessed by interview, with verification of use from medication containers at baseline and follow-up examinations. Women were classified as continuous users, partial (intermittent) users, or nonusers. Rates of change in BMD were measured at the total hip and two subregions (average 4.4 years between examinations) and at the calcaneus (average 5.7 years between examinations). RESULTS: After adjustment for confounders, the average rate of decline in total hip BMD steadily increased from -0.70%/year in nonusers to -0.87%/year in partial AED users to -1.16%/year in continuous AED users (p value for trend = 0.015). Higher rates of bone loss were also observed among continuous AED users at subregions of the hip and at the calcaneus. In particular, continuous phenytoin users had an adjusted 1.8-fold greater mean rate of loss at the calcaneus compared with nonusers of AED (-2.68 vs -1.46%/year; p < 0.001) and an adjusted 1.7-fold greater mean rate of loss at the total hip compared with nonusers of AED (-1.16 vs -0.70%/year; p = 0.069). CONCLUSIONS: Continuous AED use in elderly women is associated with increased rates of bone loss at the calcaneus and hip. If unabated, the rate of hip bone loss among continuous AED users is sufficient to increase the risk of hip fracture by 29% over 5 years among women age 65 years and older.

Incident vertebral fractures and mortality in older women: a prospective study.

Older persons who have prevalent vertebral fractures have an increased risk of mortality. It is not known whether incident vertebral fractures are also associated with an increased risk of mortality. To determine whether older women with incident vertebral fractures have an increased risk of mortality, we conducted a prospective cohort study of 7233 community-dwelling older women aged 65 years or older who were enrolled in the Study of Osteoporotic Fractures. We measured incident vertebral fractures by radiographic morphometry of paired lateral spine X-rays taken an average of 3.7 years apart. We also collected information on baseline prevalent vertebral fractures; calcaneal bone density; anthropometric measures; and demographic, medical history, and lifestyle variables. Overall mortality was assessed and confirmed by receipt of death certificates. Over an average of 3.7 years, 389 (5.4%) women developed at least one incident vertebral fracture. During an additional 8 years of follow-up, 1617 (22%) women died. Women with at least one new fracture had an age-adjusted 32% increased risk of mortality (RH=1.32; 95% CI=1.10-1.58, P=0.003) compared to those without incident vertebral fractures. After adjustment for weight loss, physical frailty markers, and nine other predictors of mortality, there was no longer an independent association between incident vertebral fractures and mortality (RH=1.06; 95% CI=0.88 1.28). Older women with incident vertebral fractures have an increased risk of mortality that may be explained by weight loss and physical frailty.

Effects of current and discontinued estrogen replacement therapy on hip structural geometry: the study of osteoporotic fractures.

It is assumed that estrogen influences bone strength and risk of fractures by affecting bone mineral density (BMD). However, estrogen may influence the mechanical strength of bones by altering the structural geometry in ways that may not be apparent in the density. Repeated dual energy X-ray absorptiometry (DXA) hip scan data were analyzed for bone density and structural geometry in elderly women participating in the Study of Osteoporotic Fractures (SOF). Scans were studied with a hip structural analysis program for the effects of estrogen replacement therapy (ERT) on BMD and structural geometry. Of the 3,964 women with ERT-use data, 588 used ERT at both the start and end of the approximately 3.5-year study, 1,203 had past use which was discontinued by clinic visit 4, and 2,163 women had never used ERT. All groups lost BMD at the femoral neck, but the reduced BMD among users of ERT was entirely due to subperiosteal expansion and not bone loss, whereas both bone loss and expansion occurred in past or nonusers. BMD increased 0.8%/year at the femoral shaft among ERT users but decreased 0.8%/year among nonusers. Section moduli increased at both the neck and shaft among ERT users but remained unchanged in past and nonusers. Current, but not past, use of estrogen therapy in elderly women seems to increase mechanical strength of the proximal femur by improving its geometric properties. These effects are not evident from changes in femoral neck BMD.

Structural adaptation to changing skeletal load in the progression toward hip fragility: the study of osteoporotic fractures.

Longitudinal, dual-energy X-ray absorptiometry (DXA) hip data from 4187 mostly white, elderly women from the Study of Osteoporotic Fractures were studied with a structural analysis program. Cross-sectional geometry and bone mineral density (BMD) were measured in narrow regions across the femoral neck and proximal shaft We hypothesized that altered skeletal load should stimulate adaptive increases or decreases in the section modulus (bending strength index) and that dimensional details would provide insight into hip fragility. Weight change in the approximately 35 years between scan time points was used as the primary indicator of altered skeletal load. "Static" weight was defined as within 5% of baseline weight, whereas "gain" and 'loss" were those who gained or lost >5%, respectively. In addition, we used a frailty index to better identify those subjects undergoing changing in skeletal loading. Subjects were classified as frail if unable to rise from a chair five times without using arm support. Subjects who were both frail and lost weight (reduced loading) were compared with those who were not frail and either maintained weight (unchanged loading) or gained weight (increased loading). Sixty percent of subjects (n = 2,559) with unchanged loads lost BMD at the neck but not at the shaft, while section moduli increased slightly at both regions. Subjects with increasing load (n = 580) lost neck BMD but gained shaft BMD; section moduli increased markedly at both locations. Those with declining skeletal loads (n = 105) showed the greatest loss of BMD at both neck and shaft; loss at the neck was caused by both increased loss of bone mass and greater subperiosteal expansion; loss in shaft BMD decline was only caused by greater loss of bone mass. This group also showed significant declines in section modulus at both sites. These results support the contention that mechanical homeostasis in the hip is evident in section moduli but not in bone mass or density. The adaptive response to declining skeletal loads, with greater rates of subperiosteal expansion and cortical thinning, may increase fragility beyond that expected from the reduction in section modulus or bone mass alone.

Correlates of attributing new disability to old age. Study of Osteoporotic Fractures Research Group.

OBJECTIVES: To describe women who attribute new disability to old age and to identify demographic, medical, behavioral, and psychosocial characteristics that correlate with attributing new disability to old age. DESIGN: Prospective cohort study with 4-year follow-up. SETTING: Four geographic regions of the United States. PARTICIPANTS: 9704 women aged > or = 67 years participating in the Study of Osteoporotic Fractures. Of these, 657 who reported no disability at baseline but at follow-up reported difficulty carrying out 1 or more of 13 functional activities were eligible for our analysis. MEASUREMENTS: All women reporting difficulty in any functional activity at follow-up were asked "What is the main condition that causes you to have difficulty or prevents you from (doing the activity)?" and were shown a card listing 14 medical conditions as well as the option "old age," from which they could choose only one response. Women attributing difficulty or inability in 1 or more functional activities to old age were classified as attributing new disability to old age. We examined the relationship between attributing new disability to old age and the following characteristics measured at baseline: age, level of education, medical comorbidity, cognitive function, body mass index (BMI), gait speed, grip strength, visual acuity, physical activity level, smoking status, social network level, and depressed mood. RESULTS: Overall, 13.5% of women attributed new disability to old age. Age was a strong independent correlate of attributing new disability to old age: compared with women age 67 to 69, the odds of attributing new disability to old age for women age 70 to 79 was 3.6 times as large (95% confidence interval [CI] = 1.6-8.3), and for women age 80 or over was 5.5 times as large (95% CI = 2.1-14.7). The only other characteristic that remained an independent correlate of attributing new disability to old age was grip strength; for each decile decrease in grip strength, a woman's odds of attributing new disability to old age increased by 9% (odds ratio [OR] = 1.09, 95% CI = 1.01-1.19). CONCLUSIONS: Despite great advances in geriatric medicine, old age is still perceived as a causal agent in functional decline, especially among our oldest patients. Further study is needed to determine whether, how often, and under what circumstances older adults who attribute new disability to old age have medical conditions amenable to interventions that could preserve their functioning and improve their quality of life.

A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women. Study of Osteoporotic Fractures Research Group.

BACKGROUND: Different sources of dietary protein may have different effects on bone metabolism. Animal foods provide predominantly acid precursors, whereas protein in vegetable foods is accompanied by base precursors not found in animal foods. Imbalance between dietary acid and base precursors leads to a chronic net dietary acid load that may have adverse consequences on bone. OBJECTIVE: We wanted to test the hypothesis that a high dietary ratio of animal to vegetable foods, quantified by protein content, increases bone loss and the risk of fracture. DESIGN: This was a prospective cohort study with a mean (+/-SD) of 7.0+/-1.5 y of follow-up of 1035 community-dwelling white women aged >65 y. Protein intake was measured by using a food-frequency questionnaire and bone mineral density was measured by dual-energy X-ray absorptiometry. RESULTS: Bone mineral density was not significantly associated with the ratio of animal to vegetable protein intake. Women with a high ratio had a higher rate of bone loss at the femoral neck than did those with a low ratio (P = 0.02) and a greater risk of hip fracture (relative risk = 3.7, P = 0.04). These associations were unaffected by adjustment for age, weight, estrogen use, tobacco use, exercise, total calcium intake, and total protein intake. CONCLUSIONS: Elderly women with a high dietary ratio of animal to vegetable protein intake have more rapid femoral neck bone loss and a greater risk of hip fracture than do those with a low ratio. This suggests that an increase in vegetable protein intake and a decrease in animal protein intake may decrease bone loss and the risk of hip fracture. This possibility should be confirmed in other prospective studies and tested in a randomized trial.

Risk for fracture in women with low serum levels of thyroid-stimulating hormone.

BACKGROUND: Biochemical evidence of hyperthyroidism may be associated with low bone mass, particularly in older postmenopausal women, but no prospective studies of thyroid function and subsequent fracture risk have been done. OBJECTIVE: To examine the association between low levels of thyroid-stimulating hormone (TSH) and fracture in older women. DESIGN: Prospective cohort study with case-cohort sampling. SETTING: Four clinical centers in the United States. PATIENTS: 686 women older than 65 years of age from a cohort of 9704 women recruited from population-based listings between 1986 and 1988. MEASUREMENTS: Baseline assessment of calcaneal bone mass, spine radiography, and history of thyroid disease. Spine radiography was repeated after a mean follow-up of 3.7 years; nonspine fractures were centrally adjudicated. Thyroid-stimulating hormone was measured in sera obtained at baseline from 148 women with new hip fractures, 149 women with new vertebral fractures, and a subsample of 398 women randomly selected from the cohort. RESULTS: After adjustment for age, history of previous hyperthyroidism, self-rated health, and use of estrogen and thyroid hormone, women with a low TSH level (0.1 mU/L) had a threefold increased risk for hip fracture (relative hazard, 3.6 [95% CI, 1.0 to 12.9]) and a fourfold increased risk for vertebral fracture (odds ratio, 4.5 [CI, 1.3 to 15.6]) compared with women who had normal TSH levels (0.5 to 5.5 mU/L). After adjustment for TSH level, a history of hyperthyroidism was associated with a twofold increase in hip fracture (relative hazard, 2.2 [CI, 1.0 to 4.4]), but use of thyroid hormone itself was not associated with increased risk for hip fracture (relative hazard, 0.5 [CI, 0.2 to 1.3]). CONCLUSIONS: Women older than 65 years of age who have low serum TSH levels, indicating physiologic hyperthyroidism, are at increased risk for new hip and vertebral fractures. Use of thyroid hormone itself does not increase risk for fracture if TSH levels are normal.

Update on the epidemiology of osteoporosis.

Osteoporosis is a major public health problem that affects the entire aging population. This report provides an update on the epidemiology of osteoporosis and its associated fractures. Published studies from 1997 to the present are highlighted. The current US prevalence estimates for osteoporosis, trends in fracture incidence rates, and latest reports on the morbidity, mortality, and costs attributable to osteoporotic fractures are discussed. Recent advances in our understanding of risk factors associated with osteoporosis and related fractures are reviewed. Special attention is paid to the rapid progress being made in the field of genetics, the growing importance of nutrition, and the new questions being raised as to the influence of hormonal factors on bone mineral density and fracture risk. New studies linking osteoporosis to several other important diseases in women including breast cancer, osteoarthritis, and stroke are also reviewed.

Urinary incontinence: does it increase risk for falls and fractures? Study of Osteoporotic Fractures Research Group.

OBJECTIVE: To determine if urge urinary incontinence is associated with risk of falls and non-spine fractures in older women. METHODS: Type and frequency of incontinent episodes were assessed by 6,049 community-dwelling women using a self-completed questionnaire. Postcards were subsequently mailed every 4 months to inquire about falls and fractures. Incident fractures were confirmed by radiographic report. Logistic and proportional hazard models were used to assess the independent association of urge urinary incontinence and risk of falling or fracture. RESULTS: The mean age of the women was 78.5 (+/- 4.6) years. During an average follow-up of 3 years, 55% of women reported falling, and 8.5% reported fractures. One-quarter of the women (1,493) reported weekly or more frequent urge incontinence, 19% (1,137) reported weekly or more frequent stress incontinence, and 708 (12%) reported both types of incontinence. In multivariate models, weekly or more frequent urge incontinence was associated independently with risk of falling (odds ratio = 1.26; 95% confidence interval (CI), 1.14-1.40) and with non-spine nontraumatic fracture (relative hazard 1.34; 95% CI, 1.06-1.69; P = .02). Stress incontinence was not associated independently with falls or fracture. CONCLUSIONS: Weekly or more frequent urge incontinence was associated independently with an increased risk of falls and non-spine, nontraumatic fractures in older women. Urinary frequency, nocturia, and rushing to the bathroom to avoid urge incontinent episodes most likely increase the risk of falling, which then results in fractures. Early diagnosis and appropriate treatment of urge incontinence may decrease the risk of fracture.