Diuretic use and bone mineral density in older USA men: the osteoporotic fractures in men (MrOS) study

Molecular mechanisms, physiological roles, and therapeutic implications of ion fluxes in bone cells: Emphasis on the cation-Cl- cotransporters

Bone turnover diseases are exceptionally prevalent in human and come with a high burden on physical health. While these diseases are associated with a variety of risk factors and causes, they are all characterized by common denominators, that is, abnormalities in the function or number of osteoblasts, osteoclasts, and/or osteocytes. As such, much effort has been deployed in the recent years to understand the signaling mechanisms of bone cell proliferation and differentiation with the objectives of exploiting the intermediates involved as therapeutic preys. Ion transport systems at the external and in the intracellular membranes of osteoblasts and osteoclasts also play an important role in bone turnover by coordinating the movement of Ca²⁺ , PO₄ ^2- , and H⁺ ions in and out of the osseous matrix. Even if they sustain the terminal steps of osteoformation and osteoresorption, they have been the object of very little attention in the last several years. Members of the cation-Cl^- cotransporter (CCC) family are among the systems at work as they are expressed in bone cells, are known to affect the activity of Ca²⁺ -, PO₄ ^2- -, and H⁺ -dependent transport systems and have been linked to bone mass density variation in human. In this review, the roles played by the CCCs in bone remodeling will be discussed in light of recent developments and their potential relevance in the treatment of skeletal disorders.

Drugs Causing Bone Loss

Drugs may cause bone loss by lowering sex steroid levels (e.g., aromatase inhibitors in breast cancer, GnRH agonists in prostate cancer, or depot medroxyprogestone acetate - DMPA), interfere with vitamin D levels (liver inducing anti-epileptic drugs), or directly by toxic effects on bone cells (chemotherapy, phenytoin, or thiazolidinedions, which diverts mesenchymal stem cells from forming osteoblasts to forming adipocytes). However, besides effects on the mineralized matrix, interactions with collagen and other parts of the unmineralized matrix may decrease bone biomechanical competence in a manner that may not correlate with bone mineral density (BMD) measured by dual energy absorptiometry (DXA).Some drugs and drug classes may decrease BMD like the thiazolidinediones and consequently increase fracture risk. Other drugs such as glucocorticoids may decrease BMD, and thus increase fracture risk. However, glucocorticoids may also interfere with the unmineralized matrix leading to an increase in fracture risk, not mirrored in BMD changes. Some drugs such as selective serotonin reuptake inhibitors (SSRI), paracetamol, and non-steroidal anti-inflammatory drugs (NSAIDs) may not per se be associated with bone loss, but fracture risk may be increased, possibly stemming from an increased risk of falls stemming from effects on postural balance mediated by effects on the central nervous system or cardiovascular system.This paper performs a systematic review of drugs inducing bone loss or associated with fracture risk. The chapter is organized by the Anatomical Therapeutic Chemical (ATC) classification.

Long-term thiazide use and risk of low-energy fractures among persons with Alzheimer's disease-nested case-control study

We investigated the association between thiazide use and the risk of low-energy fractures among community dwellers with Alzheimer's disease. Longer use was associated with a decreased risk of low-energy fractures. This study extends the previous knowledge of reduced fracture risk of thiazides to persons with Alzheimer's disease.

INTRODUCTION

To investigate the association between thiazide use and the risk of low-energy fractures (LEF), and hip fracture among community dwellers with Alzheimer's disease (AD). No prior study has evaluated the effect of thiazides on LEF risk of AD patients.

METHODS

LEF cases were identified from the MEDALZ study, including all community-dwelling persons diagnosed with AD in Finland 2005-2011. During the follow-up from AD diagnoses until the end of 2015, cases with LEF (N = 10,416) and hip fracture (N = 5578) were identified. LEF cases were matched with up to three controls without LEF, according to time since AD diagnosis, age and gender. Thiazide use identified from the Prescription register data was modeled with PRE2DUP method. Current use was defined in 0-30 days' time window before the fracture/matching date, and duration of current use was assessed. The association between thiazide exposure and LEFs was assessed with conditional logistic regression.

RESULTS

Current thiazide use was observed in 10.5% of LEF cases and 12.5% of controls. Current thiazide use was associated with a decreased risk of LEF (adjusted OR [aOR] 0.83, 95% CI 0.77-0.88). In terms of the duration of use, no association was observed with short-term use (< 1 year or 1-3 years), while longer use (> 3 years) was associated with a reduced risk of LEF (aOR 0.77, 95% CI 0.71-0.83) and hip fracture (aOR 0.68, 95% CI 0.60-0.78).

CONCLUSIONS

Our study extends the previous knowledge of reduced fracture risk of thiazides to persons with AD, a population with significantly increased background risk of fractures.

Decreasing trend of bone mineral density in US multiethnic population: analysis of continuous NHANES 2005-2014

Studies examining recent bone mineral density (BMD) trends in the US population are limited. In our study, we found that age-adjusted mean BMD among US men and women was stable from 2005 to 2010, but then declined in 2013-2014. We also explored factors associated with decreasing BMD in recent years.

INTRODUCTION

Osteoporosis prevalence in the USA declined between 1988 and 2006, while the declining trend in hip fracture may have plateaued in 2013-2014. We aimed to examine whether there has been a corresponding change in BMD trajectory for the US population.

METHODS

Continuous National Health and Nutrition Examination Survey (NHANES) data from 2005-2006 to 2013-2014 were analyzed to examine BMD trends among US men and women aged 30 years and older and among different race/ethnicity subgroups. ANOVA and Bonferroni adjustments were used to examine the differences in mean BMD, and multiple linear regressions adjusting for potential confounding effects were employed to examine BMD trends.

RESULTS

After age standardization, the mean BMD of the femur neck for the first three NHANES cycles was stable (all p > 0.1) in both men and women, but significantly decreased in 2013-2014, from 0.864 g/cm2 to 0.846 g/cm2 (p = 0.0025) in men and from 0.789 to 0.771 g/cm2 (p = 0.03) in women. The overall mean femur neck BMD in 2013-2014 was significantly lower than that in earlier survey cycles in both men and women, even after adjusting for multiple covariates, including age, race, physical activity, previous fracture, BMI, and other variables. Similar results were observed in subgroup analyses of race and sensitivity analyses.

CONCLUSIONS

Age-adjusted mean BMD decreased in 2013-2014 in both men and women, and this significant decrease was also observed in sensitivity and subgroup analyses. The decreased BMD in 2013-2014 still remained significant even after being adjusted for multiple potentially confounding effects.

Serum Sodium and Cognition in Older Community-Dwelling Men

BACKGROUND AND OBJECTIVES

Mild hyponatremia is a common finding in older adults; however, the association of lower serum sodium with cognition in older adults is currently unknown. We determined whether lower normal serum sodium is associated with cognitive impairment and risk of cognitive decline in community-dwelling older men.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Five thousand four hundred thirty-five community-dwelling men aged ≥65 years who participated in Osteoporotic Fractures in Men, a cohort study with a median follow-up for cognitive function of 4.6 years, were included in this analysis. Multivariable logistic regression was used to examine the association between baseline fasting serum sodium levels and the odds of prevalent cognitive impairment (cross-sectional analysis; modified Mini-Mental Status [3MS] score <1.5 SD [<84] below or Trail Making Test Part B time >1.5 SD above the mean [>223 seconds]) and cognitive decline (prospective analysis [n=3611]; decrease in follow-up 3MS score or increase in Trails B time >1.5 SD of the mean score/time change [>9 or >67 seconds]).

RESULTS

Participants were aged 74±6 years with a fasting mean serum sodium level of 141±3 mmol/L. Fifteen percent (n=274), 12% (n=225), and 13% (n=242) had prevalent cognitive impairment in tertiles 1, 2, and 3, respectively. After adjustment, lower serum sodium was associated with prevalent cognitive impairment (tertile 1 [126-140 mmol/L] versus tertile 2 [141-142 mmol/L], odds ratio [OR], 1.30; 95% confidence interval [95% CI], 1.06 to 1.61). Fourteen percent (n=159), 10% (n=125), and 13% (n=159) had cognitive decline in tertiles 1, 2, and 3, respectively. Lower serum sodium was also associated with cognitive decline (tertile 1 versus tertile 2, OR, 1.37; 95% CI, 1.06 to 1.77). Tertile 3 (143-153 mmol/L) was additionally associated with cognitive decline. Results were similar in sensitivity analyses according to clinical cut-offs and by quartiles.

CONCLUSIONS

In community-dwelling older men, serum sodium between 126-140, and 126-140 or 143-153 mmol/L, are independently associated with prevalent cognitive impairment and cognitive decline, respectively.

Osteoporosis in men: findings from the Osteoporotic Fractures in Men Study (MrOS)

The lifespan of men is increasing and this is associated with an increased prevalence of osteoporosis in men. Osteoporosis increases the risk of bone fracture. Fractures are associated with increased disability and mortality, and public health problems. We review here the study of osteoporosis in men as obtained from a longitudinal cohort of community-based older men, the Osteoporotic Fractures in Men Study (MrOS).

25-Hydroxyvitamin D depletion does not exacerbate MPTP-induced dopamine neuron damage in mice

Recent clinical evidence supports a link between 25-hydroxyvitamin D insufficiency (serum 25-hydroxyvitamin D [25(OH)D] levels <30 ng/mL) and Parkinson's disease. To investigate the effect of 25(OH)D depletion on neuronal susceptibility to toxic insult, we induced a state of 25(OH)D deficiency in mice and then challenged them with the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). We found there was no significant difference between control and 25(OH)D-deficient animals in striatal dopamine levels or dopamine transporter and tyrosine hydroxylase expression after lesioning with MPTP. Additionally, we found no difference in tyrosine hydroxylase expression in the substantia nigra pars compacta. Our data suggest that reducing 25(OH)D serum levels in mice has no effect on the vulnerability of nigral dopaminergic neurons in vivo in this model system of parkinsonism.

Thiazide diuretics and the risk of hip fracture

BACKGROUND

Thiazide diuretics are one of the most commonly prescribed antihypertensive agents worldwide. Thiazides reduce urinary calcium excretion. Chronic ingestion of thiazides is associated with higher bone mineral density. It has been suggested that thiazides may prevent hip fracture. However, there are concerns that diuretics, by increasing the risk of fall in elderly, could potentially negate its beneficial effects on hip fracture.

OBJECTIVES

To assess any association between the use of thiazide diuretics and the risk of hip fracture in adults.

SEARCH STRATEGY

We searched eligible studies up to December 2008 in MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), the Cumulative Index to Nursing and Allied Health Literature (CINAHL), International Pharmaceutical Abstracts, the Database of Abstracts of Review of Effects (DARE) and reference lists of previous reviews and included studies.

SELECTION CRITERIA

All randomized controlled trials and observational studies, which assessed the association between thiazide diuretic use and hip fracture.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the selection criteria, extracted data and assessed risk of bias of each study selected.  The results were summarized descriptively and quantitatively. Cohort studies and case control studies were analysed separately.

MAIN RESULTS

No randomized control trials were found. Twenty-one observational studies with nearly four hundred thousand participants were included. Six of them were cohort studies and 15 were case-control studies. Two cohort studies appear to involve the same cohort so there were only 5 unique ones. The risk of bias was assessed with the Newcastle-Ottawa Scale (NOS). Five cohort studies had low risk of bias and one had moderate risk of bias. Seven case control studies had low risk of bias and 8 had moderate risk of bias. Meta-analysis of cohort studies showed that thiazide use was associated with a reduction in risk of hip fracture by 24%, pooled RR 0.76 (95% CI 0.64-0.89; p = 0.0009). We chose not to provide a pooled summary statistics for case-control studies because of high heterogeneity (Tau(2) = 0.03, I(2) = 62%, p = 0.0008).

AUTHORS' CONCLUSIONS

Thiazides appear to reduce the risk of hip fracture based on observational studies. Randomized controlled trials are needed to confirm these findings.  

Older men's knowledge of osteoporosis and the prevalence of risk factors

It has been estimated that up to 45% of men in the United States have low bone density. Yet, only a few studies have examined men's knowledge of bone health and disease. Men's knowledge of sex-specific issues related to osteoporosis is especially not well understood. We surveyed 1535 community-dwelling men with a mean age of 79 yr. The assessed risk factors included a current diagnosis of low bone mass, positive history for fracture, recent level of physical activity, and current medications with the potential to affect bone health. Knowledge about male risk factors for osteoporosis was also assessed, including the effects of advancing age, frame size, fracture risk, calcium and Vitamin D supplementation, low testosterone level, and treatment for prostate cancer. Within this sample, only 11% of the men reported a current diagnosis of low bone mass, whereas 11% reported a prior hip fracture. Only 5% of the sample reported taking some type of Food and Drug Administration-approved medication for osteoporosis. In the aggregate, the participating men answered only 39% of the 6 male osteoporosis-knowledge questions correctly. It is imperative that bone health promotion campaigns that have educated many women effectively now expand their focus to advance the bone health of men also.

Mapping the prescriptiome to fractures in men--a national analysis of prescription history and fracture risk

SUMMARY

A nationwide case-control study was performed in 62,865 men aged 50+ using fracture data from the national hospital discharge register to screen all redeemed prescriptions in the past 5 years for significant mapping to fracture risk, employing measures to control for false discovery rate.

INTRODUCTION

Osteoporosis in men is frequently related to alcohol abuse, hypogonadism, hypercalciuria, or the use of glucocorticoids. Very limited information is available on the impact of other medications on fracture risk in men.

METHODS

We conducted a nationwide population-based case-control study collecting fracture data from the Danish National Hospital Discharge Register and prescriptions from the National Prescriptions Database (1995-2000). We included men aged 50+ years, with hospital-treated fractures in the year 2000 (n = 15,716), and age- and sex-matched controls (n = 47,149).

RESULTS

We identified 3.2 million redemptions of prescriptions for 1,073 different drugs. The analysis confirmed associations between fracture risk and use of sedatives, anti-epileptics, anti-psychotics, anxiolytics, SSRI, opioids and other analgesics, loop diuretics, and glucorticoids. New associations were also found. We observed an odds ratio (OR [95% CI] for any fracture) for fracture in users of dopaminergic agents (1.6 [1.3-1.9]) and iron compounds (1.2 [1.1-1.5]). The largest impact on fracture risk at population level was exerted by loop diuretics and analgesics.

CONCLUSIONS

An array of drugs is associated with fracture risk in men. The "prescriptiome" analysis can be used as a surveillance tool for drug-induced osteoporosis and in the planning of preventive measures.