Secondary hyperparathyroidism and mortality in hip fracture patients compared to a control group from general practice

Preoperative Vitamin D Deficiency is Associated with Increased One-Year Mortality in Chinese Geriatric Hip Fracture Patients - A Propensity Score Matching Study

BACKGROUND

Vitamin D deficiency is a common comorbidity in geriatric hip fracture patients. However, there is still an ongoing debate regarding the influence of preoperative Vitamin D status on postoperative mortality in hip fracture patients.

METHODS

Elderly patients (≥60 years) who underwent surgical interventions for unilateral hip fracture from 2015 to 2020 in our center were included. We retrospectively retrieved the demographic data from the electronic medical database. Preoperative serum total 25-hydroxy-Vitamin D was set as the independent variable and patients were classified as the Vitamin D deficiency (<20ng/mL) and the control groups consequently. Clinical outcomes include all-cause mortality, walking ability, and major postoperative complications in the first postoperative year. Propensity score matching (PSM) was performed in a ratio of 1:1 in the two groups for further comparison.

RESULTS

A total of 210 patients were included and 121 patients (57.6%) were diagnosed with Vitamin D deficiency. Patients in the Vitamin D deficiency group were much older and therefore preferred peripheral nerve block, and had significantly higher proportions of females, preoperative dementia, higher ASA grade, and lower baseline serum albumin level. Overall, 79 patients were identified in the Vitamin D deficiency and control groups after PSM, respectively. Patients diagnosed with Vitamin D deficiency showed a significantly higher one-year mortality (21.5% vs 6.3%, P=0.011) and a much lower one-year independent walking rate (67.1% vs.84.8%, P=0.016) after the matching. Regarding the dataset before PSM and after PSM, the AUC for serum Vitamin D for predicting one-year mortality was 0.656 (P=0.006) and 0.695 (P=0.002), respectively.

CONCLUSION

Our retrospective PSM-design study provides new evidence that Vitamin D deficiency was associated with a significantly higher mortality and poor walking ability in the first year after surgical intervention based on southern Chinese populations.

Comparison of Prognostic Value of 10 Biochemical Indices at Admission for Prediction Postoperative Myocardial Injury and Hospital Mortality in Patients with Osteoporotic Hip Fracture

Aim: To evaluate the prognostic impact at admission of 10 biochemical indices for prediction postoperative myocardial injury (PMI) and/or hospital death in hip fracture (HF) patients. Methods: In 1273 consecutive patients with HF (mean age 82.9 ± 8.7 years, 73.5% women), clinical and laboratory parameters were collected prospectively, and outcomes were recorded. Multiple logistic regression and receiver-operating characteristic analyses (the area under the curve, AUC) were preformed, the number needed to predict (NNP) outcome was calculated. Results: Age ≥ 80 years and IHD were the most prominent clinical factors associated with both PMI (with cardiac troponin I rise) and in-hospital death. PMI occurred in 555 (43.6%) patients and contributed to 80.3% (49/61) of all deaths (mortality rate 8.8% vs. 1.9% in non-PMI patients). The most accurate biochemical predictive markers were parathyroid hormone > 6.8 pmol/L, urea > 7.5 mmol/L, 25(OH)vitamin D < 25 nmol/L, albumin < 33 g/L, and ratios gamma-glutamyl transferase (GGT) to alanine aminotransferase > 2.5, urea/albumin ≥ 2.0 and GGT/albumin ≥ 7.0; the AUC for developing PMI ranged between 0.782 and 0.742 (NNP: 1.84−2.13), the AUC for fatal outcome ranged from 0.803 to 0.722, (NNP: 3.77−9.52). Conclusions: In HF patients, easily accessible biochemical indices at admission substantially improve prediction of hospital outcomes, especially in the aged >80 years with IHD.

Relatively low and moderate pre-fracture serum 25-hydroxyvitamin D levels associated with the highest survival in elderly hip fracture patients in Finland: a minimum 3-year follow-up

The association between serum 25-hydroxyvitamin D level and post-fracture mortality indicates beneficial relatively high serum 25-hydroxyvitamin D concentrations. A 1-year cohort study on 245 hip fracture patients in Finland indicated the lowest 3-year mortality and highest survival among patients with serum 25-hydroxyvitamin D level of 50-74 nmol/L.

PURPOSE

To explore pre-fracture serum 25-hydroxyvitamin D level as a factor associated with post-fracture survival among a cohort of hip fracture patients in Finland.

METHODS

A prospectively collected cohort of hip fracture patients (n = 245, 70% women) from two hospitals was followed for 3.2 post-hip fracture years. Serum 25-hydroxyvitamin D was measured in admission to the hospital and classified: < 50, 50-74, 75-99, and ≥ 100 nmol/L. Survival was analyzed with a Bayesian multivariate model. Relative survival was explored with the life table method according to serum 25-hydroxyvitamin D. Mortality according to serum 25-hydroxyvitamin D level and to the hospital was calculated.

RESULTS

Mortality in the patients with serum 25-hydroxyvitamin D level of 50-74 nmol/L was significantly lower than in all other patients together at every post-fracture year. The most important factors for survival were age under 85 years; living in an actual/private home; serum 25-hydroxyvitamin D level of 50-74 nmol/L, followed by 75-99 nmol/L; ASA classes 1-2 and 3; and female sex. The mean age of patients with serum 25-hydroxyvitamin D level of 50-99 nmol/L was significantly higher than in other levels. Relative survival was highest in men, women, and patients in hospital B with serum 25-hydroxyvitamin D level of 50-74 nmol.

CONCLUSION

The highest 3-year survival and the lowest mortality in this cohort appeared in patients with pre-fracture serum 25-hydroxyvitamin D level of 50-74 nmol/L. This result differs from similar studies and is lower than the recommended level of 25-hydroxyvitamin D among hip fracture patients. The results should be examined in future research with larger data.

Bone metabolism subgroups identified as hip fracture patients via clustering

PURPOSE

The aim of the study was to describe the bone metabolism status that underlies a hip fracture.

METHODS

Estimated glomerular filtration rate (e-GFR), calcium (Ca), phosphorus (P), total (ALP) and bone specific alkaline phosphatase (b-ALP), intact parathyroid hormone (i-PTH), 25-hydroxy-vitamin D (25OHD), total procollagen type I amino-terminal propeptide (PINP), and N-terminal peptide of collagen I (NTx), measured at admission in 272 hip fracture patients, were ex post analyzed by K-means clustering and principal component analysis and were evaluated by a clinician.

RESULTS

Four components, mainly consisting of b-ALP, PINP, ALP, and NTx; e-GFR and P; i-PTH and 25OHD; and Ca explained about 70% of the variability. A total of 184 patients clustered around a centroid (A) with low 25OHD (13.2 ng/ml), well-preserved kidney function (e-GFR=67.19 ml/min/1.73m²), normal Ca, P, i-PTH and bone markers, with the exception of slightly increased NTx (24.82nMBCE). Cluster B (n=70) had increased i-PTH (93.38 pg/ml), moderately decreased e-GFR, very low 25OHD (8.68 ng/dl), and high bone turnover (b-ALP 28.46 U/L, PINP 69.87 ng/ml, NTx 31.3nMBCE). Cluster C (n=17) also had hyperparathyroidism (80.35 pg/ml) and hypovitaminosis D (9.15 ng/ml), low e-GFR(48.89 ml/min/1.73m²), and notably high ALP (173 U/L) and bone markers (b-ALP 44.64 U/L, PINP 186.98 ng/ml, NTx 38.28nMBCE). According to the clinician, 62 cases clearly had secondary hyperparathyroidism.

CONCLUSIONS

Based on serum measurements, the dominant patterns of bone metabolism were normal bone turnover with high normal NTx, and secondary hyperparathyroidism related to chronic kidney disease and hypovitaminosis D. The bone formation markers, e-GFR, NTx, and P composed the most important factors.

Neck of Femur Fracture in Young Patients With End-Stage Renal Disease and Hyperparathyroidism: A Report of Three Cases and Proposed Treatment Algorithm

Secondary hyperparathyroidism is a complication arising from untreated end-stage renal disease (ESRD). It can invariably lead to osteoporosis and subsequently cause pathological neck of femur (NOF) fracture. Despite being young, osteosynthesis in neck of femur fractures of these patients often leads to nonunion and implant failure due to severely osteoporotic bone. We present our experience in managing three young patients with ESRD and secondary hyperthyroidism who sustained NOF fractures. All three patients were successfully treated and showed no complication at one year post-operation. Based on our experience and literature review, we propose a simple algorithm to guide the management of these patients.

Diabetes, Diabetic Complications, and Phosphate Toxicity: A Scoping Review

This article presents a scoping review and synthesis of research findings investigating the toxic cellular accumulation of dysregulated inorganic phosphate-phosphate toxicity-as a pathophysiological determinant of diabetes and diabetic complications. Phosphorus, an essential micronutrient, is closely linked to the cellular metabolism of glucose for energy production, and serum inorganic phosphate is often transported into cells along with glucose during insulin therapy. Mitochondrial dysfunction and apoptosis, endoplasmic reticulum stress, neuronal degeneration, and pancreatic cancer are associated with dysregulated levels of phosphate in diabetes. Ectopic calcification involving deposition of calcium-phosphate crystals is prevalent throughout diabetic complications, including vascular calcification, nephropathy, retinopathy, and bone disorders. A low-glycemic, low-phosphate dietary intervention is proposed for further investigations in the treatment and prevention of diabetes and related diabetic pathologies.

Usefulness of simple biomarkers at admission as independent indicators and predictors of in-hospital mortality in older hip fracture patients

INTRODUCTION

The data on predictive value of the routinely obtained preoperative biochemical parameters in hip fracture (HF) patients are limited. The aims of this study were to examine in older HF patients (1) the relationships between a broad set of routine laboratory parameters at admission and in-hospital mortality, and (2) evaluate the prognostic value the biomarkers and clinical characteristics (alone or in combination) provide to predict a fatal outcome.

PATIENTS AND METHODS

In 1820 consecutive patients with low-trauma osteoporotic HF aged >60 years (mean age 82.8 ± 8.1 years; 76.4% women; 65% community-dwelling) 35 laboratory variables along with 20 clinical and socio-demographic characteristics at admission were analysed. The validation cohort included data on 455 older (≥60 years of age) HF patients (mean age 82.1 ± 8.0 years, 72.1% women).

RESULTS

The mortality rate was 6% (n = 109). On univariate analysis 14 laboratory and 8 clinical parameters have been associated with in-hospital mortality. Multiple regression analyses determined 7 variables at admission as independent indicators of a fatal outcome: 4 biomarkers (albumin <33 g/L; alanine aminotransferase/gamma-glutamyl transferase ratio [GGT/ALT] >2.5; parathyroid hormone [PTH] >6.8 pmol/L; 25(OH)vitamin D < 25 nmol/L) and 3 pre-fracture clinical conditions (history of myocardial infarction, chronic kidney disease [GFR <60 ml/min/1.73 m²] and chronic obstructive pulmonary disease); the area under the receiver operating characteristic curve (AUC) was 0.75 (95%CI 0.70-0.80). The risk of in-hospital death was 1.6-2.6 times higher in subjects with any of these risk factors (RFs), and increased by 2.6-6.0-fold in patients with any two RFs (versus no RFs). The mortality rate increased stepwise as the number of RFs increased (from 0.43% -none RF to 16.8%- ≥4RF). The prognostic value of a single RF was low (AUC ≤0.635) but combination of 2 or more RFs improved the prediction significantly; AUC reached 0.84(95%CI 0.77-0.90) when ≥4 RFs (versus 0-1RF) were present. In the validated and main cohorts the number of predicted by 1, 2, 3 or ≥4 RFs and observed deaths were practically similar.

CONCLUSIONS

In HF patients, seven easily identifiable at admission characteristics, including 4 biomarkers, are strong and independent indicators of in-hospital mortality and can be used for risk stratification and individualised management.

Elderly with proximal hip fracture present significantly lower levels of 25-hydroxyvitamin D

OBJECTIVE

To compare serum 25-hydroxyvitamin D (25[OH]D) levels, a serum marker of vitamin D3, between patients with and without proximal hip fracture.

METHODS

This was a case-control study in which serum samples of 25(OH)D were obtained from 110 proximal hip fracture inpatients and 231 control patients without fractures, all over 60 years of age. Levels of 25(OH)D lower than or equal to 20 ng/mL were considered deficient; from 21 ng/mL to 29 ng/mL, insufficient; and above 30 ng/mL, sufficient. Sex, age, and ethnicity were considered for association with the study groups and 25(OH)D levels.

RESULTS

Patients with proximal hip fracture had significantly lower serum 25(OH)D levels (21.07 ng/mL) than controls (28.59 ng/mL; p = 0.000). Among patients with proximal hip fracture, 54.5% had deficient 25(OH)D levels, 27.2% had insufficient levels, and only 18.2% had sufficient levels. In the control group, 30.3% of patients had deficient 25(OH)D levels, 30.7% had insufficient levels, and 38.9% had sufficient levels. Female patients had decreased serum 25(OH)D levels both in the fracture group and in the control group (19.50 ng/mL vs. 26.94 ng/mL; p = 0.000) when compared with male patients with and without fracture (25.67 ng/mL vs. 33.74 ng/mL; p = 0.017). Regarding age, there was a significant association between 25(OH)D levels and risk of fracture only for the age groups 71-75 years and above 80 years.

CONCLUSION

Patients with proximal hip fracture had significantly decreased serum 25(OH)D levels when compared with the control group. Female patients had significantly lower serum 25(OH)D levels in both groups.

Patient and system factors of mortality after hip fracture: a scoping review

Background

Several patient and health system factors were associated with the risk of death among patients with hip fracture. However, without knowledge of underlying mechanisms interventions to improve survival post hip fracture can only be designed on the basis of the found statistical associations.

Methods

We used the framework developed by Arksey and O’Malley and Levac et al. for synthesis of factors and mechanisms of mortality post low energy hip fracture in adults over the age of 50 years, published in English, between September 1, 2009 and October 1, 2014 and indexed in MEDLINE. Proposed mechanisms for reported associations were extracted from the discussion sections.

Results

We synthesized the evidence from 56 articles that reported on 35 patient and 9 system factors of mortality post hip fracture. For 21 factors we found proposed biological mechanisms for their association with mortality which included complications, comorbidity, cardiorespiratory function, immune function, bone remodeling and glycemic control.

Conclusions

The majority of patient and system factors of mortality post hip fracture were reported by only one or two articles and with no proposed mechanisms for their effects on mortality. Where reported, underlying mechanisms are often based on a single article and should be confirmed with further study. Therefore, one cannot be certain whether intervening on such factors may produce expected results.

Perioperative risk factors in patients with a femoral neck fracture - influence of 25-hydroxyvitamin D and C-reactive protein on postoperative medical complications and 1-year mortality

Background

This study examined the association of 25-hydroxyvitamin D (25(OH)D) and C-reactive protein (CRP) with postoperative medical complications and one year mortality of elderly patients sustaining a low-energy cervical hip fracture scheduled for surgery. We hypothesized that vitamin D deficiency and CRP in these patients might be associated with an increased 1-year mortality.

Methods

The prospective single-center cohort study included 209 patients with a low-energy medial femoral neck fracture; 164 women aged over 50 years and 45 men aged over 60 years. Referring to 1-year mortality and postoperative medical complications multiple logistic regression analysis including 10 co-variables (age, sex, BMI, ASA, creatinine, CRP, leukocytes hemoglobin, 25(OH)D, vitamin D supplementation at follow-up) was performed.

Results

Vitamin D deficiency was prevalent in 87 % of all patients. In patients with severe (<10 ng/ml) and moderate (10–20 ng/ml) vitamin D deficiency one year mortality was 29 % and 13 %, respectively, compared to 9 % in patients with > 20 ng/ml 25(OH)D levels (p =0.027). Patients with a mild (CRP 10–39.9 mg/l) or active inflammatory response (CRP ≥ 40 mg/l) showed a higher one year mortality of 33 % and 40 % compared to 16 % in patients with no (CRP < 10 mg/l) inflammatory response (p = 0.002). Multiple logistic regression analysis identified CRP (OR 1.01, 95 % CI 1.00-1.02; p = 0.007), but not 25(OH)D (OR 0.97, 95 % CI 0.89-1.05; p = 0.425) as an independent predictor for one year mortality. 20 % of patients suffered in-hospital postoperative medical complications (i.e. pneumonia, thromboembolic events, etc.). 25(OH)D (OR 0.89, 95 % CI 0.81–0.97; p = 0.010), but not CRP (OR 1.01, 95 % CI 1.00-1.02; p = 0.139), was identified as an independent risk factor.

Conclusion

In elderly patients with low-energy cervical hip fracture, 25(OH)D is independently associated with postoperative medical complications and CRP is an independent predictor of one year mortality.

Vitamin D Deficiency Is Highly Concomitant but Not Strong Risk Factor for Mortality in Patients Aged 50 Year and Older with Hip Fracture

Background

The purpose of this study was to ascertain the prevalence of vitamin D deficiency and risk factors associated with mortality in patients ≥50-year-of-age with hip fractures.

Methods

A total of 489 patients ≥50-year-of-age who sustained a hip fracture from January 2010 to October 2014 were followed-up for a minimum of 1 year. Clinical and radiological outcomes were evaluated including prevalence of vitamin D deficiency. Crude mortality rates were calculated, and the effects of different risk factors on mortality were assessed.

Results

Vitamin D deficiency was present in 76.5% of cases (n=237). The prevalence of vitamin D insufficiency was 12.3%, and only 11.2% of patients had normal vitamin D levels. Accumulated mortality was 11% (54 patients) at 1 year. A univariate analysis showed that vitamin D deficiency (P=0.012), age (P<0.001), BMI (P<0.001), type of management (P<0.001), American Society of Anesthesiologists (ASA) score (P=0.009), pre-fracture ambulatory status (P<0.001), and osteoporosis (P<0.001) were associated with mortality. A multivariate analysis performed using a Cox proportional hazards model demonstrated that ASA score (P=0.001) and pre-fracture ambulatory status (P=0.011) were independently associated with mortality after hip fracture.

Conclusions

We did not find a relationship between serum 25-hydroxy-vitamin D levels and mortality after hip fracture, although we observed a high prevalence of vitamin D deficiency and a significant association with mortality in the univariate analysis.

Associations of vitamin D deficiency with postoperative gait and mortality among patients with fractures of the proximal femur

Objective

To assess whether serum vitamin D concentration is associated with gait status and mortality among patients with fractures of the proximal femur, six months after suffering the fracture.

Methods

Consecutive patients aged ≥65 years with fractures of the proximal femur, who were admitted to the orthopedics and traumatology ward of our service between January and December 2011, were prospectively evaluated. Clinical, radiological, epidemiological and laboratory analyses were performed, including vitamin D. The patients underwent surgery and were followed up as outpatients, with return visits 15, 30, 60 and 180 days after discharge, at which the outcomes of gait and mortality were evaluated.

Results

Eighty-eight patients were evaluated. Two of them were excluded because they presented oncological fractures. Thus, 86 patients of mean age 80.2 ± 7.3 years were studied. In relation to serum vitamin D, the mean was 27.8 ± 14.5 ng/mL, and 33.7% of the patients presented deficiency of this vitamin. In relation to gait, univariate and multivariate logistic regression showed that vitamin D deficiency was not associated with gait recovery, even after adjustment for gender, age and type of fracture (OR: 1.463; 95% CI: 0.524–4.088; p = 0.469). Regarding mortality, Cox regression analysis showed that vitamin D deficiency was not related to its occurrence within six months, even in multivariate analysis (HR: 0.627; 95% CI: 0.180–2.191; p = 0.465).

Conclusion

Serum vitamin D concentration was not related to gait status and/or mortality among patients with fractures of the proximal femur, six months after suffering the fracture.

Parathyroid hormone is significantly associated with body fat compartment in men but not in women following a hip fracture

BACKGROUND AND AIMS

Parathyroid hormone (PTH) exerts several actions beyond mineral metabolism and may affect body composition. The aim of our study was to assess the association between serum PTH and body fat compartment in hip fracture patients.

METHODS

We studied 575 of 630 inpatients with hip fracture consecutively admitted to our Rehabilitation ward. Dual-energy X-ray absorptiometry (DXA) was used to measure body composition. DXA scan was performed 18.5 ± 8.6 (mean ± SD) days after hip fracture occurrence. A blood sample was collected within 4 days after DXA scan. In each subject, we evaluated PTH, 25-hydroxyvitamin D, calcium, phosphate, albumin, magnesium, and creatinine. Glomerular filtration rate was estimated by a conventional formula.

RESULTS

In the 57 men, we found a significant correlation between PTH and both body mass index (BMI) (ρ = 0.37; p = 0.020) and trunk fat percentage (ρ = 0.62; p < 0.001). After multiple adjustments, we confirmed a significant association between PTH and BMI (r = 0.38; p = 0.004) or trunk fat percentage (r = 0.51; p < 0.001). In the 518 women, we found a slightly significant correlation between PTH and BMI (ρ = 0.09; p = 0.047), but after adjustments the correlation coefficient dropped to 0.02 (p = 0.69). We found no significant relationships between PTH and trunk fat percentage at bivariate correlation (ρ = 0.04; p = 0.35) or after adjustments (r = 0.04; p = 0.38).

CONCLUSIONS

PTH serum levels were robustly associated with body fat compartment in men, but not in women following a fracture of the hip. A role of PTH in affecting body composition in hip fracture men is suggested. Its potential role in male prognostic disadvantage needs further investigation.

Cardiovascular diseases in older patients with osteoporotic hip fracture: prevalence, disturbances in mineral and bone metabolism, and bidirectional links

BACKGROUND

Considerable controversy exists regarding the contribution of mineral/bone metabolism abnormalities to the association between cardiovascular diseases (CVDs) and osteoporotic fractures.

AIMS AND METHODS

To determine the relationships between mineral/bone metabolism biomarkers and CVD in 746 older patients with hip fracture, clinical data were recorded and serum concentrations of parathyroid hormone (PTH), 25-hydroxyvitamin D, calcium, phosphate, magnesium, troponin I, parameters of bone turnover, and renal, liver, and thyroid functions were measured.

RESULTS

CVDs were diagnosed in 472 (63.3%) patients. Vitamin D deficiency was similarly prevalent in patients with (78.0%) and without (82.1%) CVD. The CVD group had significantly higher mean PTH concentrations (7.6 vs 6.0 pmol/L, P < 0.001), a higher prevalence of secondary hyperparathyroidism (SPTH) (PTH > 6.8 pmol/L, 43.0% vs 23.3%, P < 0.001), and excess bone resorption (urinary deoxypyridinoline corrected by creatinine [DPD/Cr] > 7.5 nmol/μmol, 87.9% vs 74.8%, P < 0.001). In multivariate regression analysis, SHPT (odds ratio [OR] 2.6, P = 0.007) and high DPD/Cr (OR 2.8, P = 0.016) were independent indictors of CVD. Compared to those with both PTH and DPD/Cr in the normal range, multivariate-adjusted ORs for the presence of CVD were 17.3 (P = 0.004) in subjects with SHPT and 9.7 (P < 0.001) in patients with high DPD/Cr. CVD was an independent predicator of SHPT (OR 2.8, P = 0.007) and excess DPD/Cr (OR 2.5, P = 0.031). CVD was predictive of postoperative myocardial injury, while SHPT was also an independent predictor of prolonged hospital stay and in-hospital death.

CONCLUSION

SHPT and excess bone resorption are independent pathophysiological mediators underlying the bidirectional associations between CVD and hip fracture, and therefore are important diagnostic and therapeutic targets.

Impaired bone mineralization accompanied by low vitamin D and secondary hyperparathyroidism in patients with femoral neck fracture

SUMMARY

Although it is well established that a decrease in bone mass increases the risk of osteoporotic fractures, the proportion of fractures attributable to areal bone mineral density (BMD) is rather low. Here, we have identified bone mineralization defects together with low serum 25-hydroxyvitamin D (25-(OH) D) levels as additional factors associated with femoral neck fractures.

INTRODUCTION

Osteoporotic fractures of the femoral neck are associated with increased morbidity and mortality. Although it is well established that a decrease in bone mass increases the risk of osteoporotic fractures, the proportion of fractures attributable to areal BMD is rather low. To identify possible additional factors influencing femur neck fragility, we analyzed patients with femoral neck fracture.

METHODS

We performed a detailed clinical and histomorphometrical evaluation on 103 patients with femoral neck fracture including dual-energy X-ray absorptiometry, laboratory parameters, and histomorphometric and bone mineral density distribution (BMDD) analyses of undecalcified processed biopsies of the femoral head and set them in direct comparison to skeletal healthy control individuals.

RESULTS

Patients with femoral neck fracture displayed significantly lower serum 25-(OH) D levels and increased serum parathyroid hormone (PTH) compared to controls. Histomorphometric analysis revealed not only a decreased bone volume and trabecular thickness in the biopsies of the patients, but also a significant increase of osteoid indices. BMDD analysis showed increased heterogeneity of mineralization in patients with femoral neck fracture. Moreover, patients with femoral neck fracture and serum 25-(OH) D levels below 12 μg/l displayed significantly thinner trabecular bone.

CONCLUSION

Taken together, our data suggest that impaired bone mineralization accompanied by low serum 25-(OH) D levels is of major importance in the etiology of femoral neck fractures. Therefore, balancing serum 25-(OH) D levels and thereby normalizing PTH serum levels may counteract pronounced mineralization defects and might decrease the incidence of femoral neck fractures.

Parathyroid hormone response to severe vitamin D deficiency is sex associated: an observational study of 571 hip fracture inpatients

OBJECTIVES

To investigate the association between sex and parathyroid hormone response to severe vitamin D deficiency after hip fracture.

DESIGN

Cross-sectional study.

SETTING

Rehabilitation hospital in Italy.

PARTICIPANTS

571 consecutive inpatients with hip fracture and severe vitamin D deficiency (serum 25-hydroxyvitamin D < 12ng/ml), without hypercalcemia or estimated glomerular filtration rate (GFR) < 15ml/min.

MEASUREMENTS

In each patient we assessed PTH (by two-site chemiluminescent enzyme-labelled immunometric assay), 25-hydroxyvitamin D (by immunoenzymatic assay), albumin-adjusted total calcium, phosphate, magnesium, and creatinine 21.3 ± 6.1 (mean ± SD) days after fracture occurrence. Functional level was assessed using the Barthel index. PTH response to vitamin D deficiency was classified as either secondary hyperparathyroidism (serum PTH >75pg/ml) or functional hypoparathyroidism, i.e., inappropriate normal levels of PTH (≤75pg/ml).

RESULTS

Among the 571 patients, 336 (59%) had functional hypoparathyroidism, whereas 235 (41%) had secondary hyperparathyroidism. PTH status was significantly different between sexes (p=0.003): we found functional hypoparathyroidism in 61% of women and 43% of men (secondary hyperparathyroidism in 39% of women and 57% of men). The significance of the between-sex difference was maintained after adjustment for age, estimated GFR, phosphate, albumin-adjusted total calcium, albumin, Barthel index scores, 25-hydroxyvitamin D, and hip fracture type (either cervical or trochanteric). The adjusted odds ratio was 1.85 (95%CI from 1.09 to 3.13; p=0.023).

CONCLUSIONS

Data shows that PTH response to vitamin D deficiency was sex-associated following a fracture of the hip. The higher prevalence of secondary hyperparathyroidism may play a role in the known prognostic disadvantage found in hip-fracture men.