Serum levels of vitamin D, sunlight exposure, and knee cartilage loss in older adults: the Tasmanian older adult cohort study

Association of vitamin D status with knee pain and radiographic knee osteoarthritis

OBJECTIVE

The objective of the present study was to explore the association of serum vitamin D concentration and polymorphism in the vitamin D receptor (VDR), with knee pain and radiographic knee osteoarthritis (OA) among men and women in a large population-based UK cohort study.

METHODS

Seven hundred and eighty-seven participants in the Hertfordshire Cohort Study (399 men, 388 women; mean age 65.6±2.7 years) underwent a questionnaire on knee pain and radiographic knee examination. This study examined the association of Fok1, Cdx2 and Apa1 polymorphism in the gene for the VDR and serum 25(OH)D concentration with knee pain and radiographic knee OA by a generalized estimating equations population averaged logistic regression analysis in the Hertfordshire Cohort Study.

RESULTS

There were no associations of Fok1, Cdx2 and Apa1 polymorphisms of the VDR with knee OA except for Aa for Apa1 compared with AA [Odds ratio (OR) 0.59, 95% confidence interval (CI) 0.36-0.95, P=0.031]. While, ff for Fok1 (OR 1.60, 95% CI 1.07-2.39, P=0.022) and AA for Cdx2 polymorphism (OR 2.21, 95% CI 1.07-4.56, P=0.032) was significantly associated with higher prevalence of knee pain compared with FF for Fok1 and GG for Cdx2, respectively. None of these are statistically significant after adjusting for the three polymorphisms tested. 25(OH)D level was not significantly associated with radiographic knee OA, while, low tertile of 25(OH)D level tended to be associated with knee pain compared with high tertile of 25(OH)D level.

CONCLUSION

The present cross-sectional study using a large-scale population from the Hertfordshire Cohort study indicated that vitamin D may be associated with pain rather than radiographic change, but the evidence for an association between vitamin D genetic variation and pain in knee OA is very weak in the present study. Further replication of our results will be required to elucidate the association of vitamin D and knee OA.

Association of 25-hydroxyvitamin D with the incidence of knee and hip osteoarthritis: a 22-year follow-up study

OBJECTIVE

In the light of conflicting results from previous studies on the role of vitamin D, we studied serum 25-hydroxyvitamin D [25(OH)D] with regard to its prediction of incident knee and hip osteoarthritis (OA).

METHODS

The study population (n = 805) consisted of participants of a national health examination survey who had undergone baseline and follow-up clinical examinations at intervals of 20-23 years. Knee and hip OA were diagnosed on the basis of a standardized clinical examination by physicians with the same diagnostic criteria at baseline and follow-up. Information on covariates, including age, sex, season of blood draw, education, body mass index (BMI), physical workload, leisure time physical activity, smoking history, and previous injuries, was collected at baseline. Serum 25(OH)D concentrations were determined from baseline serum samples kept frozen at -20°C.

RESULTS

We found no significant association between serum 25(OH)D level and the risk of incident knee or hip OA. However, a statistically significant interaction between season of blood draw and serum 25(OH)D emerged when predicting the development of definite knee OA (p = 0.004). After adjusting for all the covariates, the relative odds (95% confidence interval) of developing definite knee OA per increment of 1 SD (20.7 ng/mL) in winter season 25(OH)D was 1.57 (1.10-2.27), whereas for summer season sera the corresponding rate was 0.53 (0.28-1.00).

CONCLUSION

The results do not support the hypothesis that a low level of serum 25(OH)D contributes to the development of OA. Instead, our study suggests that season is a potent effect modifier of 25(OH)D, which merits attention in future research.

Inter-dependence of vitamin D levels with serum lipid profiles in multiple sclerosis

OBJECTIVE

To assess whether vitamin D (VD) levels in multiple sclerosis (MS) patients exhibit inter-dependence with serum lipid profile variables (serum cholesterol, high-density lipoprotein or HDL, low-density lipoprotein or LDL, and triglycerides) and to investigate the associations with clinical disability measures.

METHODS

The study population consisted of consecutive 178 MS patients (age: 46.6±10.6 years; disease duration: 13.8±10.3 years). The patients were assessed for fasting lipid profile and VD obtained concomitantly. Neurological disability using the Expanded Disability Status Scale (EDSS) was obtained within ±6 months of the lipid profile. The associations between the HDL, LDL, total cholesterol and total cholesterol to HDL ratio with deseasonalized VD levels and their relationships with EDSS and the MS Severity Score (MSSS) were analyzed using regression methods.

RESULTS

The cholesterol to HDL ratio was associated with the deseasonalized VD (r(p)=-0.18, p=0.019) and VD3 (r(p)=-0.17, p=0.028) levels. The probability of VD3 sufficiency was associated with HDL>60 mg/dl status (p=0.015, OR=0.42, 95% CI=0.20 to 0.86) and with total cholesterol to HDL ratio<3.5 status (p<0.001, OR=4.07, 95% CI=2.03 to 8.15). In stepwise regression models, EDSS was associated with total cholesterol to HDL ratio (p=0.008, r(p)=0.21) whereas MSSS was associated with deseasonalized 25-hydroxy VD3 (p=0.021, r(p)=-0.18). The probability of EDSS≥4.0 was also associated with total cholesterol to HDL ratio (p=0.011, OR=1.59, 95% CI=1.11 to 1.26).

CONCLUSIONS

The results suggest inter-dependence between the total cholesterol to HDL ratio and deseasonalized vitamin D levels in MS patients. Disability measures in MS are also associated with these inter-dependent variables.

Vitamin D and hyperparathyroidism in obesity

BACKGROUND

Low vitamin D status and hyperparathyroidism occur in obesity and may be involved in pathogenesis of obesity-associated comorbid conditions.

AIMS

Our aims were to determine in obesity whether there was vitamin D insufficiency, assessed by serum 25-hydroxyvitamin D (s25D) and serum PTH (sPTH) and whether it related to comorbid conditions.

METHODS

We conducted a case-control study of 48 women having bariatric surgery and 50 healthy women frequency matched for race, age, year, and season of study. Height, weight, s25D, sPTH, serum 1,25-dihydroxyvitamin D (s1,25D), serum bone alkaline phosphatase, serum cross-linked N-telopeptides of type 1 collagen, and serum calcium, phosphate, creatinine, glucose, and insulin were measured, and comorbid conditions were documented from patient files.

RESULTS

Weight (140 vs. 76 kg, P < 0.001), sPTH (44.4 vs. 25.6 pg/ml, P < 0.001), s1,25D (39 vs. 24 pg/ml, P < 0.001), serum bone alkaline phosphatase (19 vs. 12 ng/ml, P < 0.001), serum cross-linked N-telopeptides of type 1 collagen (9.6 vs. 7.9 nm bone collagen equivalents, P = 0.007), serum phosphate (3.45 vs. 3.24 mg/dl, P = 0.043), and serum creatinine (1.05 vs. 0.87 mg/dl, P < 0.001) were higher, and s25D (16 vs. 23 ng/ml, P <.001) was lower in bariatric-surgery women than control women. s25D was lower in bariatric-surgery women than controls in summer (17 vs. 26 ng/ml, P < 0.0001) but not winter (15 vs. 18 ng/ml, P > 0.2). Multiple regression analysis demonstrated that weight predicted s25D (P < 0.001) and sPTH (P = 0.001), but s25D did not predict sPTH or the presence of comorbid conditions except for osteoarthritis.

CONCLUSION

Women having bariatric surgery had lower s25D and higher sPTH. The major determinant of s25D and sPTH was weight. Hyperparathyroidism in obesity did not indicate vitamin D insufficiency. Low s25D was not associated with comorbid conditions, apart from osteoarthritis.

Older Mayan residents of the western highlands of Guatemala lack sufficient levels of vitamin D

Vitamin D (VitD) levels in older Mayans are currently unknown. Geographic factors, for example, residences in areas receiving ample sunlight at high altitudes and latitudes near the equator, would favor optimum VitD levels, whereas demographic factors, for example, darker skin pigmentation, clothing practices, and older age, would favor low 25-hydroxy-vitamin D, or 25(OH)D, levels. Conjecturing that demographic factors affecting VitD status might outweigh geographic factors in this population, we hypothesized that older Mayans have suboptimal values of 25(OH)D. We also hypothesized that older Mayans in rural areas would have higher VitD levels than would their urban counterparts. Blood samples were collected from 108 healthy older Mayans (mean age, 69 years) from urban (n = 84, 50% male) and rural settings (n = 24, 50% male) during the summer of 2008 in the highlands of Quetzaltenango, Guatemala. We assessed 25(OH)D concentrations by radioimmunoassay in a US-based laboratory. Mean (SD) serum 25(OH)D values were 53.3 (15.0) nmol/L, and lower 25(OH)D values were associated with increasing age (r = -0.58, P = .004). Of all subjects, 3.7% (n = 4) maintained an optimal status of 25(OH)D (>80 nmol/L), 50% (n = 54) had values between 50 and 80 nmol/L, and 46.3% (n = 50) had levels less than 50 nmol/L. Urban subjects had nonsignificantly higher 25(OH)D values (55.0 ± 15.3 nmol/L) than did rural subjects (47.4 ± 12.4 nmol/L, P = .228). Men had significantly higher values (58.2 ± 16.5 nmol/L) than did women (48.4 ± 11.6 nmol/L, P = .001). We conclude that despite residing in an optimal geographic location to receive adequate sunlight exposure, most older Guatemalan Mayans in Quetzaltenango have suboptimal levels of VitD.

Prevention and treatment of vitamin D deficiency in Dutch psychogeriatric nursing home residents by weekly half-body UVB exposure after showering: a pilot study

BACKGROUND

in older people, induction of cutaneous vitamin D production by ultraviolet B (UVB) exposure may be preferable to oral supplementation: it cannot cause toxic levels, it helps to prevent polypharmacy and, moreover, there are indications that UVB exposure has beneficial effects on health and well being by mechanisms other than the vitamin D pathway alone.

OBJECTIVE

the aim of this pilot study is to investigate whether weekly, half-body, UVB irradiation after showering can increase serum 25-hydroxyvitamin D (25(OH)D) to sufficient levels, in a Dutch psychogeriatric nursing home population.

METHOD

subjects were eight psychogeriatric nursing home patients, mean age: 79 ± 8. Exclusion criteria were going outdoors into the sun more than once a week, the presence of actinic or cancer skin lesions and known resistance to body contact. The intervention consisted of weekly half-body UVB irradiation, after showering, over 8 weeks, with 0.5 minimal erythemal dose (MED). Main outcome measures were change in fasting serum levels of 25(OH)D and parathyroid hormone (PTH) at 0, 2, 4 and 8 weeks.

RESULTS

at baseline, mean serum 25(OH)D was 28.5 nmol/l. Mean serum 25(OH)D levels increased to 46.5 nmol/l. Median serum PTH levels decreased by 20% after 8 weeks of treatment.

CONCLUSION

an 8 week course of weekly, frontal half-body irradiation with UVB, at 0.5 MED, leads to an significant increase in 25(OH)D serum levels, but this period is too short to reach vitamin D sufficiency.

Association between serum vitamin D deficiency and knee osteoarthritis

BACKGROUND

Insufficient levels of serum 25-hydroxyvitamin D (25-OHD) influence the knee joint cartilage and lead to development and progression of knee osteoarthritis (OA). The purpose of this study was to determine the status of serum 25-OHD levels in patients with knee OA compared with controls.

METHODS

A total of 148 patients with knee OA and 150 controls were studied. Serum 25-OHD was measured by the ELISA method and concentrations <20 ng/ml were considered as deficient levels. Mann-Whitney U test was used for comparisons of means and logistic regression analysis with calculation of odds ratio (OR) was applied to determine association.

RESULTS

The mean ages of patients and controls were 60.2 ± 12.9 and 60.1 ± 10.2 years, respectively (P = 0.23). In the entire population the mean serum 25-OHD in OA patients was not significantly lower than controls (P = 0.28), but in subgroup analysis the mean 25-OHD in OA patients aged <60 years was significantly lower than controls (23.8 ± 18.8 vs. 34.5. ± 29.6 ng/ml, P = 0.01). In this age group knee OA was significantly associated with serum 25-OHD deficiency which remained significant after adjusting for age and sex (adjusted OR = 2.26, 95% CI 1.15-4.4, P = 0.018). A greater association was observed in patients aged < 55 years (OR = 2.63, 95% CI 1.16-5.95, P = 0.01); whereas the association between OA and serum 25-OHD deficiency in patients aged ≥60 years did not reach a significant level.

CONCLUSION

These findings indicate a significant association between serum 25-OHD deficiency and knee OA in patients aged < 60 years and suggest serum 25-OHD measurement in any patient with symptoms suggestive of knee OA particularly at the initial stage of disease.

25-hydroxyvitamin D concentration, vitamin D intake and joint symptoms in postmenopausal women

INTRODUCTION

Low 25-hydroxyvitamin D (25(OH) D) concentrations have been associated with radiologic worsening of osteoarthritis in some reports. However, the results are mixed and few studies have evaluated associations between 25(OH) D concentrations and both total vitamin D intake and clinical joint symptoms.

STUDY DESIGN

Cross-sectional analyses of information from a subset of 1993 postmenopausal women obtained at baseline entry in the Women's Health Initiative Calcium plus Vitamin D clinical trial.

MAIN OUTCOME MEASURES

25(OH) D concentration, total vitamin D intake (diet plus supplements), presence and severity of joint pain and joint swelling.

RESULTS

The 25(OH) D levels were commonly low with 53% having deficient (<50 nmol/L) and only 17% having sufficient (>72 nmol/L) levels. Joint pain (reported by 74%) and joint swelling (reported by 34%) were also commonly reported. 25(OH) D concentrations were modestly correlated with total vitamin D intake (R=0.29, p<0.0001); however, considerable variability in 25(OH) D concentrations for a given vitamin D intake was seen. In adjusted linear regression models, lower serum 25(OH) D concentrations were associated with higher average joint pain score (P=0.01 for trend) with differences most apparent in the lowest 25(OH) D levels sextile.

CONCLUSIONS

Relatively low 25(OH) D levels and a high frequency of joint symptoms were common in this population of postmenopausal women. Total vitamin D intake was only modestly associated with 25(OH) D. Low serum 25(OH) D concentrations were associated with higher joint pain scores. These findings can inform the design of future intervention trials.

Not a simple fat-soluble vitamin: Changes in serum 25-(OH)D levels are predicted by adiposity and adipocytokines in older adults

OBJECTIVE

To determine the associations between body adiposity and change in serum 25-(OH)D levels over 2.6 years, and if these associations are mediated by metabolic and inflammatory factors in older adults.

METHODS

This is a longitudinal study of 859 randomly selected subjects (mean 62 years, range 51-80, 49% women). Serum 25-hydroxyvitamin D [25-(OH)D] was assessed by radioimmunoassay at baseline and 2.6 years later. Baseline serum level of leptin was assessed by radioimmunoassay and interleukin (IL)-6 by a chemiluminescent immunoassay in the first 183 subjects.

RESULTS

In multivariable analyses, body mass index, trunk fat percentage and waist-to-hip ratio were significant predictors of increased incident vitamin D deficiency [a 25-(OH)D < 50 nmol L⁻¹ at follow-up when ≥50 nmol L⁻¹ at baseline] and decreased recovery of vitamin D deficiency [a 25-(OH)D ≥ 50 nmol L⁻¹ at follow-up when < 50 nmol L⁻¹ at baseline]. Change in 25-(OH)D levels per annum was also independently predicted by baseline leptin (β: -0.09/unit, 95% CI: -0.17, -0.03), IL-6 (β: -0.68/quartile, 95% CI: -1.35, -0.02) and total cholesterol/high-density lipoprotein (HDL) ratio (β: -0.51, 95% CI: -0.88, -0.14). The associations between body adiposity measures and change in 25-(OH)D completely disappeared after adjustment for leptin, diminished after adjustment for IL-6, but remained unchanged after adjustment for total cholesterol/HDL ratio. All associations were independent of season and sun exposure.

CONCLUSIONS

Body fat is not simply a passive reservoir for 25-(OH)D. In addition to season and sun exposure, 25-(OH)D levels appear to be determined by metabolic and, to a lesser extent, inflammatory factors, and these appear to mediate the effects of adiposity on change in 25-(OH)D.

Vascular disease is associated with facet joint osteoarthritis

OBJECTIVE

Epidemiologic studies have demonstrated associations between vascular disease and spinal degeneration. We sought to examine whether vascular disease was associated with lumbar spine facet joint osteoarthritis (FJ OA) in a community-based population.

DESIGN

441 participants from the Framingham Heart Study multi-detector computed tomography (MDCT) Study were included in this ancillary study. We used a quantitative summary measure of abdominal aortic calcification (AAC) from the parent study as a marker for vascular disease. AAC was categorized into tertiles of 'no' (reference), 'low', and 'high' calcification. FJ OA was evaluated on computerised tomography (CT) scans using a four-grade scale. For analytic purposes, FJ OA was dichotomized as moderate FJ OA of at least one joint from L2-S1 vs no moderate FJ OA. We examined the association of AAC and FJ OA using logistic regression before and after adjusting for age, sex and body mass index (BMI). Furthermore, we examined the independent effect of AAC on FJ OA after including the known cardiovascular risk factors; diabetes, hypertension, hypercholesterolemia, and smoking.

RESULTS

Low AAC (OR 3.84 [2.33-6.34]; P<or=0.0001) and high AAC (9.84 [5.29-18.3]; <or=0.0001) were strongly associated with FJ OA, compared with the reference group. After adjusting for age, sex, and BMI, the association with FJ OA was attenuated for both low AAC (1.81 [1.01-3.27]; P=0.05) and high AAC (2.63 [0.99-5.23]; P=0.05). BMI and age were independently and significantly associated with FJ OA. The addition of cardiovascular risk factors to the model did not substantially change parameter estimates for either AAC tertile.

CONCLUSIONS

AACs were associated with FJ OA in this community-based population, when adjusting for epidemiologic factors associated with spinal degeneration, and cardiovascular risk factors. Potentially modifiable risk factors for facet degeneration unrelated to conventional biomechanical paradigms may exist. This study is limited by cross-sectional design; longitudinal studies are needed.

Targeting subchondral bone for treating osteoarthritis: what is the evidence?

Over the past few decades, significant progress has been made with respect to new concepts about the pathogenesis of osteoarthritis (OA). This article summarises some of the knowledge we have today on the involvement of the subchondral bone in OA. It provides substantial evidence that changes in the metabolism of the subchondral bone are an integral part of the OA disease process and that these alterations are not merely secondary manifestations, but are part of a more active component of the disease. Thus, a strong rationale exists for therapeutic approaches that target subchondral bone resorption and/or formation, and data evaluating the drugs targeting bone remodelling raise the hope that new treatment options for OA may become available.

Association of 25-hydroxyvitamin D with prevalent osteoarthritis of the hip in elderly men: the osteoporotic fractures in men study

OBJECTIVE

To examine the cross-sectional association of serum levels of 25-hydroxyvitamin D, or 25(OH)D, with prevalent radiographic hip osteoarthritis (OA) in elderly men.

METHODS

In a cohort of 1,104 elderly men from the Osteoporotic Fractures in Men Study, 25(OH)D serum levels were determined by mass spectrometry, followed by pelvic radiographs approximately 4.6 years later. Categories of vitamin D levels were defined as follows: deficiency as < or =15 ng/ml, insufficiency as 15.1-30 ng/ml, and sufficiency as >30 ng/ml. Radiographs were assessed for severity of hip OA using a summary grade of 0-4 for individual features of hip OA. Logistic regression was used to assess associations of serum 25(OH)D levels with prevalent radiographic hip OA; covariates included age, clinic site, season at the time of blood withdrawal, self-reported hip pain for >30 days, timed 6-meter walk, presence of at least 1 coexisting condition, and self-rated health status.

RESULTS

Men with radiographic hip OA had a slower 6-meter walking time (P < 0.0001), reported more hip pain (P = 0.0001), had a lower vitamin D level (P = 0.0002), and had a higher prevalence of vitamin D insufficiency (P = 0.002) and vitamin D deficiency (P = 0.012) compared with controls. Higher 25(OH)D levels were associated with a lower prevalence of radiographic hip OA (odds ratio [OR] 1.39 per 1 SD decrease in 25[OH]D, 95% confidence interval [95% CI] 1.11-1.74) after adjusting for age, season, and clinic site. Men with vitamin D insufficiency had an increased likelihood of prevalent radiographic hip OA (OR 2.19, 95% CI 1.21-3.97) compared with men with sufficient levels of 25(OH)D, and in men with vitamin D deficiency, there was a tendency toward an increased likelihood of radiographic hip OA (OR 1.99, 95% CI 0.83-4.74).

CONCLUSION

Men with vitamin D deficiencies are twice as likely to have prevalent radiographic hip OA, and therefore vitamin D therapy to augment skeletal health in the elderly is warranted.