The utility of serum 25-Hydroxyvitamin-D and body mass index in the work-up of patients presenting to a bone health clinic

Matthew R Mccarley,Gordon L Klein,Ronald W Lindsey,Kelsey L Wise,Daniel C Jupiter

doi:10.12688/f1000research.12484.1

Matthew R Mccarley, Gordon L Klein + Show 3 more

Open Access

https://doi.org/10.12688/f1000research.12484.1

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Abstract

Background: 25-hydroxyvitamin-D (25[OH]D) and Dual-energy x-ray absorptiometry (DEXA) are routinely evaluated in bone health clinics, but existing literature is conflicting with regard to whether these factors predict fragility fractures. We hypothesized that both serum 25(OH)D levels and bone density are lower in patients who have sustained fragility fracture(s) prior to initial presentation compared to those patients who have not. Methods: We reviewed the charts of 102 consecutive patients presenting to a single-center Bone Health Clinic, comprising 11 males and 91 females with a mean age of 68 and range of 50 to 92. Demographic data, serum 25(OH)D levels, fracture history, and DEXA scans were obtained at the initial visit. Results: 64 patients had previously sustained a fragility fracture, and 38 patients had not. 25(OH)D levels were similar in the fracture and non-fracture groups (37.12±17.02 ng/mL versus 38.55±16.42, p=0.676). DEXA T-scores were similar between fracture and non-fracture groups (-2.28±1.33 versus -1.82±1.1, p=0.075). Patients with rheumatoid arthritis (RA) (n=7) had lower 25(OH)D levels upon presentation (mean 22.57±8.46 versus 38.77±16.67, p=0.001). BMI was inversely correlated with 25(OH)D level (Pearson correlation [R] =-0.211, p=0.033). Age was inversely correlated with DEXA T-score (R=-0.269, p-0.009), whereas BMI was positively correlated with DEXA T-score (R=0.259, p=0.013). The other demographic variables and risk factors studied were not significantly associated with either 25(OH)D levels or DEXA T-scores. Within the fracture group, DEXA T-scores were lower for patients who had sustained a hip fracture (n=15) compared to those who had sustained a fragility fracture elsewhere (-3.12±1.02 versus -2.03±1.32, p=0.004), but their 25(OH)D levels did not differ (34.33±25.49 versus 37.98±13.69, p=0.602).Conclusions: In this cohort of patients referred to a Bone Health Clinic, serum 25(OH)D levels and DEXA T-scores did not differ between those patients who had sustained a fragility fracture from those who had not.

Highlights

Fragility fractures are defined by their low-energy nature, occurring from a fall or impact from a standing height or lower
A key explanation for this diagnostic lag is the limitations bone mineral density (BMD) measurements have in predicting fragility fracture risk via existing methods, dual-energy x-ray absorptiometry (DEXA)
Fracture and non-fracture groups did not differ with respect to any of the demographic variables evaluated

Summary

Introduction

Fragility fractures are defined by their low-energy nature, occurring from a fall or impact from a standing height or lower. They are the result of an underlying problem in the bone itself—for example, low density or abnormal remodeling—and, potentially preventable. As many as 50% of patients with fragility fractures do not have osteoporosis as defined by their bone density[3,4,5] Recognizing this limitation, the World Health Organization developed the Fracture Risk Assessment Tool (FRAX) to guide treatment and prevention strategies for fragility fractures. FRAX has been shown to underestimate fracture risk in patients with diabetes, for example, as this particular risk factor is excluded from the calculation[8]

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