Osteoporosis in South-East Asian Countries

Osteoporosis (OP) is a condition where there is low bone density and microarchitectural deterioration which can predispose to fragility fractures. There is a wealth of literature on OP from the developed countries, but less so from Asia. This review will explore the field of OP research in South-East Asia with regard to the epidemiology, the diagnosis of OP and the role of laboratory tests in the management of OP, with emphasis on 25-dihydroxyvitamin D and bone turnover markers.

Development and validation of a sunlight exposure questionnaire for urban adult Filipinos

OBJECTIVES

To develop and validate a self-reported sunlight exposure questionnaire (SEQ) for urban adult Filipinos.

METHODS

The study included adults (19-76 years old) in Metro Manila, Philippines, well-versed in the Filipino (Tagalog) language and had resided in Metro Manila for at least 1 year. Exclusion criteria included pregnancy, active skin disorders, and immunocompromised states. An expert panel created a questionnaire in Likert-scale format based on a conceptual framework and 4 existing instruments. The study proceeded in 4 phases: questionnaire item development, translation and back-translation, pretesting, and construct validity and reliability testing using factor analysis, the Cronbach alpha coefficient, and the paired t-test.

RESULTS

A 25-item, self-administered, Filipino (Tagalog) SEQ answerable using a 4-point Likert scale was created. The questionnaire was administered to 260 adult participants twice at a 2-week interval, with all participants completing both the first and second rounds of testing. All questionnaire items possessed adequate content validity indices of at least 0.86. After factor analysis, 3 questionnaire domains were identified: intensity of sunlight exposure, factors affecting sunlight exposure, and sun protection practices. Internal consistency was satisfactory for both the overall questionnaire (Cronbach alpha, 0.80) and for each of the domains (Cronbach alpha, 0.74, 0.71, and 0.72, respectively). No statistically significant differences were observed in the responses between the first and second rounds of testing, indicating good test-retest reliability.

CONCLUSIONS

We developed a culturally-appropriate SEQ with sufficient content validity, construct validity, and reliability to assess sunlight exposure among urban adult Filipinos in Metro Manila, Philippines.

Is vitamin D deficiency a public health concern for low middle income countries? A systematic literature review

PURPOSE

Vitamin D deficiency has been receiving increasing attention as a potential public health concern in low and lower-middle income countries (LMICs), of which there are currently 83. We aimed to conduct a comprehensive systematic literature review (SLR) of available data on vitamin D status and prevalence of vitamin D deficiency in all 83 LMICs.

METHODS

We followed the general methodology for SLRs in the area of serum 25-hydroxyvitamin D. Highest priority was placed on identifying relevant population-based studies, followed by cross-sectional studies, and to a lesser extent case-control studies. We adopted the public health convention that a prevalence of vitamin D deficiency (serum 25-hydroxyvitamin D < 25/30 nmol/L) at > 20% in the entire population and/or at-risk population subgroups (infants, children, women of child-bearing age, pregnancy) constitutes a public health issue that may warrant intervention.

RESULTS

Our SLR revealed that of the 83 LMICs, 65% (n = 54 countries) had no published studies with vitamin D data suitable for inclusion. Using data from the remaining third, a number of LMICs had evidence of excess burden of vitamin D deficiency in one or more population subgroup(s) using the above convention (Afghanistan, Pakistan, India, Tunisia and Mongolia) as well as possibly other LMICs, albeit with much more limited data. Several LMICs had no evidence of excess burden.

CONCLUSION

Vitamin D deficiency is a public health issue in some, but certainly not all, LMICs. There is a clear need for targeting public health strategies for prevention of vitamin D deficiency in those LMICs with excess burden.

Attitudes, Behaviors and Beliefs of Urban Adult Filipinos on Sunlight Exposure: A Qualitative Study

Objective

To explore the attitudes, behaviors, and beliefs of urban adult Filipinos on sunlight exposure as an initial step in the development and validation of a culturally-appropriate questionnaire.

Methodology

Focus groups were conducted among urban Filipinos 19 years old and above (n=38). The transcribed results underwent qualitative content and thematic analyses and were used to develop a conceptual framework.

Results

Qualitative analysis revealed four main themes of sunlight exposure: internal influences, external influences, perceived benefits, and perceived risks. Both internal and external influences lead to perceived risks and benefits. Consequently, the perceived benefits (or lack) of sunlight exposure influence an individual’s attitude towards vitamin D supplementation; whereas the perceived risks of sunlight exposure influence an individual’s attitude towards the need for sun protection.

Conclusion

The attitudes, behaviors and beliefs of urban adult Filipinos on sunlight exposure are influenced by both internal and external factors, that in turn lead to perceived risks and benefits. An increased awareness of these factors is necessary to establish future recommendations on proper sunlight exposure in this population. The study results will be used to develop and validate a culturally-appropriate sunlight exposure questionnaire.

Vitamin D status and its relationship with bone mineral density in a healthy Iranian population

Objectives

Considering the controversial results regarding the relationship between vitamin D levels and bone mineral density in different populations, the present study was designed to evaluate this correlation in a healthy Iranian population.

Methods

Using a random cluster sample of apparently healthy men and women, this multicenter cross-sectional study was carried out among 4450 individuals living in urban areas of five major cities in Iran. Bone mineral density (BMD) values at different sites were analyzed along with the serum levels of 25(OH)D and PTH. Analysis of variance (ANOVA) was used to estimate the main effects, through comparing the mean values of these markers based on the bone mineral density status of the study group in each sex.

Results

25(OH)D levels were inversely correlated with BMD values at total hip (r = −0.062 in men and r = −0.057 in women) and spine (r = −0.076 in men and r = −0.107 in women). After adjusting the data for age, the inverse correlation was no longer statistically significant.

Conclusion

Serum 25(OH)D levels are inversely correlated with bone mass values in both sexes.

Optimal serum concentration of 25-hydroxyvitamin D for bone health in older Korean adults

Optimal vitamin D concentrations for bone health have not been determined in the Korean population. The aim of this study was to define serum 25-hydroxyvitamin D (25[OH]D) concentrations that indicate insufficiency among older Korean adults as measured by serum intact parathyroid hormone (iPTH) concentrations and bone mineral density (BMD). We analyzed data from the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV-3), which was conducted in Korea in 2009. We enrolled 1,451 men and 1,870 women aged 49 years and above. After adjusting for variables that could potentially affect serum 25(OH)D concentrations, we found that serum iPTH concentrations began to increase at serum 25(OH)D concentrations below 12.1 ng/mL (30.2 nmol/L). In addition, total-femur BMD increased until serum 25(OH)D concentrations dropped below 20.4 ng/mL (50.9 nmol/L); no significant changes were observed thereafter. Assuming that serum 25(OH)D concentrations below 12.1 and 20.4 ng/mL represent vitamin D insufficiency, the prevalences of vitamin D insufficiency were 8.7 and 50.4 % in men and 17.9 and 66.3 % in women, respectively. Serum 25(OH)D cutoff values of 12.1 ng/mL (OR = 1.26) and 20.4 ng/mL (OR = 1.54) were associated with osteoporosis (P < 0.01); osteoporosis was not associated with a 25(OH)D cutoff value of 30 ng/mL (75.0 nmol/L). In conclusion, serum 25(OH)D concentrations of 20 ng/mL might be sufficient for bone health in older Korean adults.

Correlation of vitamin D, bone mineral density and parathyroid hormone levels in adults with low bone density

BACKGROUND

Bone mineral densiy (BMD) is known to be affected by serum 25-hydroxyvitamin D (25(OH) D) levels, intact parathyroid hormone (iPTH) levels. Indian data pertinent to above observation is scant. Our study aimed to investigate the relationships between serum 25-hydroxyvitamin D (25(OH) D) levels, intact parathyroid hormone (iPTH) levels and bone mineral density (BMD) in a cohort of Indian patients.

MATERIALS AND METHODS

Adults with or without fragility fractures with low BMD at the hip or lumbar spine were evaluated clinically along with laboratory investigations. T-scores of the hip and spine were derived from BMD-DEXA (dual-energy X-ray absorptiometry). Multivariate regression models were used to investigate the relationships between serum 25(OH) D, iPTH and BMD.

RESULTS

Total of 102 patients (male:female = 38:64) with a mean age of 62.5 ± 6.4 years were included in the study. Forty-four patients had osteopenia. Osteoporosis was present in 58 patients. The mean values for serum 25(OH) D and iPTH levels were 21.3 ± 0.5 ng/ml and 53.1 ± 22.3 pg/ml, respectively. In 84.3% of patients, serum 25(OH) D levels were below 30 ng/ml (Normal = 30-74 ng/ml), confirming vitamin D deficiency. There was no association between 25(OH) D levels and BMD at the hip or lumbar spine (P = 0.473 and 0.353, respectively). Both at the hip and lumbar spine; iPTH levels, male gender, body mass index (BMI) and age were found to be significant predictors of BMD. Patients with higher BMI had significantly lower BMD and T-score. At levels <30 ng/ml, 25(OH) D was negatively associated with iPTH (P = 0.041).

CONCLUSION

Among our cohort of patients with low BMD, no direct relationship between serum 25(OH) D levels and BMD was observed. However, a negative correlation between iPTH and 25(OH) D at serum 25(OH) D concentrations <30 ng/ml. Serum iPTH levels showed a significant negative association with BMD at the hip and lumbar spine. Our findings underscore the critical role of parathyroid hormone in bone metabolism and health.