Standardizing 25-hydroxyvitamin D data from the HunMen cohort

Standardization of 25-hydroxyvitamin D (25OHD) values is still a challenge. We propose standardization by correction of the measured 25OHD values using the linear regression bias from the National Institute of Standards and Technology (NIST) 'total' target values reported by Vitamin D External Quality Assessment Scheme (DEQAS). Our approach could perhaps be a practical solution to the anomaly surrounding non-standardized 25OHD values.

INTRODUCTION

Standardization of 25OHD values is still a challenge. We propose standardization by correction of the measured 25OHD values using the linear regression equation derived from the analysis of relationship between total 25OHD values measured by the methodology used by the laboratory and the NIST total target values (TV) reported by the DEQAS for all 5 of the DEQAS samples in a given survey.

METHODS

We applied our approach to standardize total 25OHD values of the HunMen cohort.

RESULTS

All 206 samples for the HunMen cohort were evaluated using the automated Liaison DiaSorin total 25OHD chemiluminescence immunoassay (CLIA). The timing of these measurements coincided with that of the October 2015 DEQAS survey using samples 481 to 485. Following standardization, the mean total 25OHD changed from 53 to 62 nmol/L and the prevalence of hypovitaminosis D (<75 nmol/L) decreased significantly from 84 to 72%.

CONCLUSION

A simple approach readily applicable at the routine diagnostic laboratory could perhaps be a practical solution to the anomaly surrounding non-standardized 25OHD values.

Vitamin D status in men with psoriatic arthritis: a case-control study

We determined hypovitaminosis D prevalence in men with psoriatic arthritis. This is a cross-sectional, analyst blinded, age- and sex-matched, case-control study. Men with psoriatic arthritis have significantly lower 25-hydroxyvitamin D levels. Men with psoriatic arthritis are at increased odds of suffering from hypovitaminosis D.

INTRODUCTION

Skeletal manifestations as a result of abrupted bone metabolism may be predominant in psoriatic arthritis (PsA). Vitamin D plays a vital role in maintenance of skeletal health and is known to modulate the immune system in various autoimmune diseases including PsA. The aim of the present study was to determine the prevalence of hypovitaminosis D in a treatment naïve, de novo psoriatic arthritis male cohort in a cross-sectional, analyst blinded, age- and sex-matched, case-control study.

METHODS

25 hydroxyvitamin D (25OHD), parathyroid (PTH), osteocalcin (OC) and C-terminal telopeptides of type-I collagen (CTx) levels, and lumbar spine and femoral neck bone mineral density were compared between 53 PsA and controls.

RESULTS

The prevalence of hypovitaminosis D (25 hydroxyvitamin D (25OHD) levels <75 nmol/L) was 81 and 57 % in the PsA and control groups, respectively. Compared to the healthy controls, 25OHD (67.2 (12-137) nmol/L vs. 51.9 (15-95) nmol/L; p = 0.001) was significantly lower, and osteocalcin (13.6 (5-33) μg/L vs. 18.2 (6-35) μg/L; p = 0.003) and C-terminal telopeptides of type-I collagen (0.20 (0.01-0.71) μg/L vs. 0.28 (0.06-0.69) μg/L; p = 0.008) were significantly higher in the PsA group. A significant association was found between hypovitaminosis D and PsA; the odds for patients with PsA of having hypovitaminosis D was 3.297 (95 % confidence interval 1.372 to 7.922).

CONCLUSION

The results of this study suggest that men with PsA have significantly lower 25-hydroxyvitamin D levels, and furthermore, men with PsA are at statistically significant increased odds of suffering from hypovitaminosis D.

Prevalence and seasonal variation of hypovitaminosis D and its relationship to bone metabolism in healthy Hungarian men over 50 years of age: the HunMen Study

This study reports a high prevalence of hypovitaminosis D and low bone mineral density (BMD) in a healthy Hungarian male cohort over 50 years of age. Men with 25-hydroxyvitamin D levels of <75 nmol/L had a significantly higher 10-year hip and major osteoporotic fracture probability using the country-specific fracture risk assessment (FRAX) algorithm.

INTRODUCTION

The aim of this study is to characterize the prevalence and seasonal variation of hypovitaminosis D and its relationship to bone metabolism in healthy Hungarian men over 50 years of age.

METHODS

We determined levels of 25-hydroxyvitamin D (25-OH-D), PTH, osteocalcin (OC), C-terminal telopeptides of type-I collagen (CTX-I), procollagen type 1 amino-terminal propeptide (PINP), BMD at L1-L4 (LS) and femur neck (FN), daily dietary calcium intake, and the 10-year probability of hip fracture and a major osteoporotic fracture using the country-specific FRAX algorithm in 206 randomly selected ambulatory men.

RESULTS

The mean (range) age of the volunteers was 60 (51-81) years. The prevalence of hypovitaminosis D (25-OH-D, <75 nmol/L) was 52.9%. The prevalence of low (T-score < -1.0) BMD at the FN and LS was 45% and 35.4%, respectively. The mean (range) FRAX hip fracture and FRAX major osteoporotic fracture was 0.8% (0-9.4%) and 3.8% (1.7-16%), respectively. On comparing the vitamin D sufficient to the insufficient group, there was a statistically significant difference between the FRAX hip fracture and FRAX major osteoporotic fracture indexes. There was significant seasonal variation in the vitamin D levels; the lowest levels were measured in winter and the highest in summer.

CONCLUSIONS

A high prevalence of hypovitaminosis D and low BMD were observed in the studied Hungarian male population. This is the first study reporting higher 10-year hip and major osteoporotic fracture probability using the country-specific FRAX algorithm in individuals with hypovitaminosis D.

Hypotension during gradual blood loss: waveform variables response and absence of tachycardia

BACKGROUND

Variation in arterial pressure and plethysmographic waveforms has been shown to be predictors of cardiac output response to fluid challenge. The objective of this study was to evaluate the ability of arterial and plethysmographic waveform variables to predict hypotension during blood loss.

METHODS

Patients undergoing autologous haemodilution were studied. After anaesthesia induction, blood was withdrawn in steps of 2% of estimated circulating blood volume (ECBV). Arterial and plethysmographic waveforms were recorded and analysed offline at each step of blood withdrawal.

RESULTS

Thirty-four (29%) out of 118 studied patients tolerated 20% ECBV withdrawal without hypotension. Patients who tolerated 20% ECBV withdrawal were younger than those who did not [mean (sd): 53.8 (11.1) vs 62.7 (10.7); P<0.0001]. Patients with hypertension developed hypotension earlier than healthier patients did. There were no differences at the baseline in arterial and plethysmographic waveform variables between those who did and those who did not tolerate 20% of ECBV withdrawal. All values of variables increased significantly from the baseline after the withdrawal of 4% of ECBV (P<0.005). There were no changes in heart rate (HR), 73 (12) at the baseline and 76 (13) after 20% of ECBV withdrawal (P=0.4).

CONCLUSIONS

Arterial and plethysmographic waveform variables were augmented with increasing blood loss in all patients. Older patients, patients who received anti-hypertensive drugs, or both developed hypotension earlier than others. Baseline values were weak predictors of hypotension during stepwise blood withdrawal. No clinically significant increase in HR was observed, regardless of tolerance of arterial pressure to blood withdrawal.

Aerobic and anaerobic arm-cranking power outputs of males with lower limb impairments: relationship with sport participation intensity, age, impairment and functional classification

Fifty individuals with lower limb impairments including spinal cord injury, polio and amputations underwent aerobic and anaerobic arm-cranking tests in a standardized laboratory setting. Based on linear regression models applied with age as dependent variable aerobic performance variable including HRmax (R = 0.395, P = 0.004), and POaer (R = 0.31, P = 0.021) were subjected to ANCOVA adjusting for age in order to determine the significance of participation intensity (competitive vs leisure) and type of physical impairment. Anaerobic performance variables were not influenced by age and thereby subjected to 1-Way ANOVA with the same independent variables. Participation intensity and type of impairment significantly discriminated (P < 0.001) between athletes in all power variables. Linear regression models have shown moderate but significant (P < 0.001) relationship with functional ability (bases on International Wheelchair Basketball Federation classification system). In anaerobic mean power (MP) classification accounted for 42% of the variance, while in anaerobic peak power (PP) and aerobic Power (POaer) for 38% and 30% respectively. By means of a post hoc Tukey analysis significant differences were observed between athletes with a high level paraplegia (class 1) and those with one leg affected by polio or amputations (classes 4, 4.5). Athletes with low level paraplegia and two legs affected by polio (classes 2-3.5) had values in-between. Based on the descriptive evaluation, a three group scheme was conceptualized and resubjected to ANOVA. Significant intergroup differences were thus obtained only for PP. Descriptive PP data for each group were transformed into a five category table in order to provide reference values for fitness-estimation in males with lower limb impairments of various etiologies.