The yield of routine laboratory examination in osteoporosis evaluation in primary care.

This study evaluated the yield of routine laboratory examination in a large population of older women in primary care. The prevalence of laboratory abnormalities was low and the clinical consequences in follow-up were limited. There was a weak association of laboratory abnormalities with osteoporosis but no association with vertebral fractures and recent fractures. PURPOSE: Most osteoporosis guidelines advice routine laboratory examination. We have investigated the yield of laboratory examinations in facture risk evaluation of elderly women in primary care. METHODS: We assessed the prevalence of laboratory abnormalities and their association with risk factors for fractures, recent fractures, low bone mineral density (BMD), and prevalent vertebral fracture in 8996 women ≥ 65 years of age participating in a primary care fracture risk screening study. In a sample of 2208 of these participants, we also evaluated the medical consequences in the medical records during a follow-up period of ≥ 1 year. RESULTS: Vitamin D deficiency (< 30 nmol/L) was present in 13% and insufficiency (< 50 nmol/L) in 43% of the study sample. The prevalence of other laboratory abnormalities (ESR, calcium, creatinine, FT4) was 4.6% in women with risk factors for fractures, 6.1% in women with low BMD (T-score ≤ - 2.5), 6.0% after a prevalent vertebral fracture, 5.2% after a recent fracture and 2.6% in the absence of important risk factors for fractures. Laboratory abnormalities other than vitamin D were associated with low BMD (OR 1.4, 95%CI 1.1-1.8) but not with prevalent vertebral fractures nor recent fractures. Low BMD was associated with renal failure (OR 2.0, 95%CI 1.3-3.4), vitamin D insufficiency (OR 1.2, 95%CI 1.0-1.3) and deficiency (OR 1.3, 95%CI 1.1-.5). In the follow-up period, 82% of the laboratory abnormalities did not result in a new diagnosis or treatment reported in the medical records. CONCLUSIONS: We identified a low prevalence of laboratory abnormalities in a primary care population of older women and the majority of these findings had no medical consequences.

The Effect of a Screening and Treatment Program for the Prevention of Fractures in Older Women: A Randomized Pragmatic Trial.

Population screening for fracture risk may reduce the fracture incidence. In this randomized pragmatic trial, the SALT Osteoporosis Study (SOS), we studied whether screening for fracture risk and subsequent treatment in primary care can reduce fractures compared with usual care. A total of 11,032 women aged 65 to 90 years with ≥1 clinical risk factor for fractures were individually randomized to screening (n = 5575) or usual care (n = 5457). Participants in the screening group underwent a screening program, including bone densitometry and vertebral fracture assessment. Participants with a high 10-year fracture probability (FRAX) or a vertebral fracture were offered treatment with anti-osteoporosis medication by their general practitioner. Incident fractures as reported by questionnaires were verified with medical records. Follow-up was completed by 94% of the participants (mean follow-up = 3.7 years). Of the 5575 participants in the screening group, 1417 (25.4%) had an indication for anti-osteoporosis medication. Screening and subsequent treatment had no statistically significant effect on the primary outcome fracture (hazard ratio [HR] = 0.97; 95% confidence interval [CI] 0.87-1.08), nor on the secondary outcomes osteoporotic fractures (HR = 0.91; 95% CI 0.81-1.03), major osteoporotic fractures (HR = 0.91; 95% CI 0.80-1.04), hip fractures (HR = 0.91; 95% CI 0.71-1.15), falls (odds ratio [OR] = 0.91; 95% CI 0.72-1.15), or mortality (HR = 1.03; 95% CI 0.91-1.17). Post hoc explorative finding suggested that screening might be most effective after a recent fracture (HR = 0.65; 95% CI 0.44-0.96 for major osteoporotic fractures and HR = 0.38; 95% CI 0.18-0.79 for hip fractures). The results of this study might have been compromised by nonparticipation and medication nonadherence in the screening group. Overall, this study does not provide sufficient indications to consider screening for fracture prevention. However, we cannot exclude its clinical relevance to reduce (major) osteoporotic fractures and hip fractures because of the relatively small number of women with a treatment indication in the intervention group. © 2019 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc.

A Meta-Analysis of Trabecular Bone Score in Fracture Risk Prediction and Its Relationship to FRAX.

Trabecular bone score (TBS) is a gray-level textural index of bone microarchitecture derived from lumbar spine dual-energy X-ray absorptiometry (DXA) images. TBS is a bone mineral density (BMD)-independent predictor of fracture risk. The objective of this meta-analysis was to determine whether TBS predicted fracture risk independently of FRAX probability and to examine their combined performance by adjusting the FRAX probability for TBS. We utilized individual-level data from 17,809 men and women in 14 prospective population-based cohorts. Baseline evaluation included TBS and the FRAX risk variables, and outcomes during follow-up (mean 6.7 years) comprised major osteoporotic fractures. The association between TBS, FRAX probabilities, and the risk of fracture was examined using an extension of the Poisson regression model in each cohort and for each sex and expressed as the gradient of risk (GR; hazard ratio per 1 SD change in risk variable in direction of increased risk). FRAX probabilities were adjusted for TBS using an adjustment factor derived from an independent cohort (the Manitoba Bone Density Cohort). Overall, the GR of TBS for major osteoporotic fracture was 1.44 (95% confidence interval [CI] 1.35-1.53) when adjusted for age and time since baseline and was similar in men and women (p > 0.10). When additionally adjusted for FRAX 10-year probability of major osteoporotic fracture, TBS remained a significant, independent predictor for fracture (GR = 1.32, 95% CI 1.24-1.41). The adjustment of FRAX probability for TBS resulted in a small increase in the GR (1.76, 95% CI 1.65-1.87 versus 1.70, 95% CI 1.60-1.81). A smaller change in GR for hip fracture was observed (FRAX hip fracture probability GR 2.25 vs. 2.22). TBS is a significant predictor of fracture risk independently of FRAX. The findings support the use of TBS as a potential adjustment for FRAX probability, though the impact of the adjustment remains to be determined in the context of clinical assessment guidelines. © 2015 American Society for Bone and Mineral Research.

Physiological concentrations of insulin induce endothelin-mediated vasoconstriction during inhibition of NOS or PI3-kinase in skeletal muscle arterioles.

OBJECTIVE: To determine the roles of nitric oxide, endothelin-1 and phosphatidylinositol 3-kinase (PI3-kinase) in acute responses of isolated rat skeletal muscle arterioles to insulin. METHODS: Rat cremaster first order arterioles were separated from surrounding tissue, cannulated in a pressure myograph and responses to insulin (4 microU/ml-3.4 mU/ml) were studied without intraluminal blood or flow. RESULTS: Insulin alone did not significantly affect arteriolar diameter. Non-selective antagonism of endothelin receptors, with PD-142893, uncovered insulin-induced vasodilatation (25+/-8% from baseline at 3.4 mU/ml), which was abolished by inhibition of NO synthesis with N(G)-nitro-L-arginine (L-NA). Inhibition of NO synthesis alone uncovered insulin-induced vasoconstriction at physiological concentrations (21+/-5% from baseline diameter at 34 microU/ml), which was abolished by PD-142893. The NO donor, S-nitroso-N-acetyl-penicillamine (SNAP) inhibited insulin-induced vasoconstriction during NOS inhibition, even at a concentration that did not elicit vasodilatation itself. Inhibition of PI3-kinase, an intracellular mediator of insulin-induced NO production, with wortmannin, also uncovered insulin-induced vasoconstriction (13+/-3% from baseline at 34 microU/ml) that was abolished by PD-142893. CONCLUSIONS: Insulin induces both nitric oxide and endothelin-1 activity in rat cremaster first-order arterioles. This study demonstrates for the first time that vasoconstrictive effects of physiological concentrations of insulin during inhibition of NOS activity are mediated by endothelin and that insulin induces endothelin-1-mediated vasoconstriction in isolated skeletal muscle arterioles during inhibition of PI3-kinase. These findings support the hypothesis of altered microvascular reactivity to insulin in conditions of diminished PI3-kinase activity, a prominent feature of insulin resistance.

Prediction of vitamin D deficiency by simple patient characteristics.

BACKGROUND: Vitamin D status is currently diagnosed by measuring serum 25-hydroxyvitamin D [25(OH)D]. OBJECTIVE: This study aimed to develop a risk profile that can be used to easily identify older individuals at high risk of vitamin D deficiency. DESIGN: This study was performed within the Longitudinal Aging Study Amsterdam, an ongoing cohort study in a representative sample of the Dutch older population (n = 1509 for the development sample and n = 1100 for the validation sample). Prediction models for serum 25(OH)D concentrations <50 and <30 nmol/L were developed by using backward logistic regression. Risk scores were calculated by dividing the individual regression coefficients by the regression coefficient with the lowest ß to create simple scores. RESULTS: Serum 25(OH)D concentrations <50 and <30 nmol/L were present in 46.2% and 17.5% of participants, respectively. The model for the prediction of concentrations <50 nmol/L consisted of 13 easily assessable predictors, whereas the model for concentrations <30 nmol/L contained 10 predictors. The resulting areas under the curve (AUCs) were 0.78 and 0.80, respectively. The AUC in the external validation data set was 0.71 for the <50-nmol/L model. At a cutoff of 58 in total risk score (range: 8-97), the model predicted concentrations <50 nmol/L with a sensitivity of 61% and a specificity of 82%, whereas these values were 61% and 84%, respectively, at a cutoff of 110 in the total risk score (range: 6-204) in the model for concentrations <30 nmol/L. CONCLUSIONS: Two total risk scores, including 13 or 10 predictors that can easily be assessed, were developed and are able to predict serum 25(OH)D concentrations <50 and <30 nmol/L accurately. These risk scores may be useful in clinical practice to identify persons at risk of vitamin D deficiency.