Poor dietary consumption and limited sun exposure are risk factors for vitamin D deficiency in premenopausal Kuwaiti women: A cross-sectional study.

Background: Low serum vitamin D levels are reported constantly among females living in the Arabian Gulf countries, presumably due to their lifestyle, which limits direct sun exposure. Because Vitamin D deficiency has been implicated in a wide range of ailments, healthy females with the deficiency might be at risk for developing many health problems. Thus, the aim was to assess lifestyle risk factors for vitamin D deficiency in healthy women in Kuwait. Methods: A total of 104, disease-free, premenopausal women were recruited for assessment of their serum 25OHD and intact PTH levels. Physical examination, blood withdrawal and interviewer-administered questionnaires were used to collect the relevant data. Associations were detected statistically using nonparametric tests and logistic regression was used to identify risk factors for vitamin D deficiency. Results: Vitamin D deficiency ( < 25 nmol/L) occurred in 84.6%, and hyperparathyroidism ( ≥ 6.9 pmol/L) occurred in 25% of women, among which all were vitamin D deficient. Significant risk factors of vitamin D deficiency were nondaily milk intake (OR:25, CI%:4.2-147), no fish intake (OR:5, CI%:1-22.8), and no weekend sun exposure (OR:8.2, CI%:1.28-52.6). Having PTH ≥ 6 pmol/L was also associated with a higher likelihood of having vitamin D deficiency. Conclusion: Vitamin D deficiency is very common in disease-free, premenopausal Kuwaiti women and can be avoided by improving food consumption and obtaining more sun exposure.

Landscape Analysis of a Class of NP-Hard Binary Packing Problems.

This article presents an exploratory landscape analysis of three NP-hard combinatorial optimisation problems: the number partitioning problem, the binary knapsack problem, and the quadratic binary knapsack problem. In the article, we examine empirically a number of fitness landscape properties of randomly generated instances of these problems. We believe that the studied properties give insight into the structure of the problem landscape and can be representative of the problem difficulty, in particular with respect to local search algorithms. Our work focuses on studying how these properties vary with different values of problem parameters. We also compare these properties across various landscapes that were induced by different penalty functions and different neighbourhood operators. Unlike existing studies of these problems, we study instances generated at random from various distributions. We found a general trend where some of the landscape features in all of the three problems were found to vary between the different distributions. We captured this variation by a single, easy to calculate parameter and we showed that it has a potentially useful application in guiding the choice of the neighbourhood operator of some local search heuristics.

Vitamin D levels in schoolchildren: a cross-sectional study in Kuwait.

BACKGROUND: Ongoing studies in the Middle East, particularly in the Arabian Gulf countries, have reported extremely low levels of serum vitamin D across age and gender. In Kuwait, vitamin D deficiency is prevalent in adolescent girls and in adult women. A number of risk factors have been reported, among which gender, age, and obesity are a few. Because adequate vitamin D status is necessary to promote bone mineral accrual in childhood, and because low vitamin D levels have been associated with a wide range of health problems, there is concern that growing children with low vitamin D may be at higher risk for developing diseases. The aim of this study was to assess vitamin D levels in elementary schoolchildren. METHODS: Kuwaiti schoolchildren were recruited and assessed for their serum vitamin D, 25(OH)D, parathyroid hormone (PTH) and adjusted serum calcium (adj-Ca). Anthropometric measurements and data on lifestyle and health status were recorded during an interview. RESULTS: In a total of 199 schoolchildren, median (IQR) age was 8.5 (7.0-9.5 years), 25(OH)D was 30 (22-39 nmol/L), PTH was 4.7 (3.8-5.9 pmol/L), and adj-Ca was 2.39 (2.33-2.44 mmol/L). Boys had higher levels of 25(OH)D (18.3% vs 6.6% had levels ≥50 nmol/L) and lower levels of PTH (94.6% vs 80.2% had levels <7 pmol/L) than girls. Significant risk factors for 25(OH)D levels <25 nmol/L included being ≤8.5 years old (OR 4.95, 95% CI: 1.92-12.74), having PTH ≥7 pmol/L (OR 2.28, 95% CI: 1.17-4.46), being female (OR 2.44, 95% CI: 1.22-4.88), and being overweight or obese (OR 2.18, 95% CI: 1.11-4.26). CONCLUSIONS: The results show relatively low levels of 25(OH)D in young schoolchildren in Kuwait, with lower levels in girls. Given the association of 25(OH)D with a wide range of ailments, it is necessary to further examine the causes and risk factors of low vitamin D in this age group to prevent associated health problems.

Association of self-reported symptoms with serum levels of vitamin D and multivariate cytokine profile in healthy women.

BACKGROUND: Although a large number of studies have investigated possible relationships among serum levels of vitamin D or cytokines with disease progress and prognosis, similar studies on self-reported symptoms are still controversial. The overall objective of this study was to look into the association between serum levels of vitamin D or cytokines with self-reported symptoms related to musculoskeletal pain, sleep disorders, and premenstrual syndrome (PMS) in healthy adult women. SUBJECTS AND METHODS: Venous blood samples were collected from 117 healthy adult women, and serum levels of vitamin D, pro-inflammatory cytokines (IL-1ß, IL-6, IL-8, IL-17, IFN-γ, and TNF-α) and anti-inflammatory cytokines (IL-4, IL-10, and IL-13) were measured. Groups were tested for differences in single parameters, pro-:anti-inflammatory cytokine ratios, and differences in multivariate patterns. RESULTS: There were no significant associations between serum levels of vitamin D and any of the self-reported symptoms studied. However, serum levels of certain pro-inflammatory cytokines were significantly higher in subjects with musculoskeletal pain (IL-8, P=0.008), sleep disorders (IFN-γ, P=0.02), and PMS (IL-8 and TNF-α, P=0.009 and 0.002, respectively) compared to subjects who reported no symptoms. The pro-:anti-inflammatory cytokine ratios showed pro-inflammatory cytokine dominance in subjects with self-reported symptoms, particularly in the groups with deficient levels of vitamin D. However, the multivariate cytokine-pattern analysis was significantly different between PMS groups only. CONCLUSION: These data point to a possible role of pro-inflammatory cytokines as a contributing factor in self-reported symptoms related to musculoskeletal pain, sleep disorders, and PMS.

Association between levels of vitamin D and inflammatory markers in healthy women.

BACKGROUND: No one can deny that the biological importance of vitamin D is much beyond its classical role in bone metabolism. Several recent publications have highlighted its potential role in the functioning of the immune system. The overall objective of this study was to look into possible correlations between levels of vitamin D and inflammatory markers in sera of healthy adult women. These markers included proinflammatory cytokines (interleukin [IL]-1ß, IL-6, IL-8, IL-17, interferon [IFN]-γ, and tumor necrosis factor [TNF]-α), anti-inflammatory cytokines (IL-4, IL-10, and IL-13), as well as C-reactive protein (CRP) as a general indicator of inflammation. METHODS: Venous blood samples were collected from 118 healthy adult women and serum levels of vitamin D, CRP, proinflammatory cytokines (IL-1ß, IL-6, IL-8, IL-17, IFN-γ, and TNF-α), and anti-inflammatory cytokines (IL-4, IL-10, and IL-13) were measured. RESULTS: There were no significant direct correlations between serum levels of vitamin D and any of the inflammatory markers measured. However, subjects with deficient levels of vitamin D and high CRP produced significantly higher levels of the proinflammatory cytokines (TNF-α and IL-8) as compared to subjects with low CRP levels with nondeficient and deficient levels of vitamin D. Further, the anti-inflammatory/proinflammatory ratios suggest a role of vitamin D in maintaining an anti-inflammatory environment at low levels of CRP, an association that is weaker at high CRP levels in subjects with subclinical inflammatory situations. CONCLUSION: These data point to a possible role of vitamin D as a contributing factor in balancing cytokines toward an anti-inflammatory role in inflammatory situations.

Risk factors of low vitamin D status in adolescent females in Kuwait: implications for high peak bone mass attainment.

UNLABELLED: Risks of low vitamin D status in Kuwaiti adolescent girls are high parathyroid hormone (PTH), high waist/hip ratio, veiling and not having a private room. Low vitamin D status is likely to have a negative impact on their bone mass and accrual. INTRODUCTION: Low serum 25-hydroxyvitamin D (25OHD) levels are repeatedly found in females in the Middle East, which is a cause for concern particularly for adolescent females. This is because vitamin D has been shown to promote bone mineral accrual in adolescence. PURPOSE: The aim of this study was to assess the risk factors of low vitamin D status in adolescent females and to assess its impact on their bone mass. METHODS: Serum 25OHD and PTH were measured in 232 females. Anthropometric measurements and skin colour were obtained. Bone measurements at the lumbar spine were performed using dual-energy x-ray absorptiometry (DXA). Data on food intake, physical activity (PA) and sun exposure were taken. Binary logistic regression was used to assess the risk factors of serum 25OHD levels <25 nmol/L and multiple linear regression was used to assess the predictors of bone mineral variables. RESULTS: Median 25OHD was 19.4 nmol/L (IQR 16.4-23.68), among which 98.7 % obtained <50 nmol/L. PTH >7 pmol/L (odds ratio (OR) 4.3; 95 % CI 1.8, 10.2), not having a private room (OR 3.7; 95 % CI 1.4, 9.8), veiling (OR 2.4; 95 % CI 1.1, 5.5) and waist/hip ratio >0.75 (OR 2.1; 95 % CI 1.0, 4.3) were risk factors of low vitamin D status, whereas, height, weight, month since menarche, PTH, animal protein intake and PA were independent predictors of bone mineral content (p < 0.05). CONCLUSION: Low vitamin D status is prevalent in Kuwaiti adolescent females, which may have a negative impact on their bone mineralization and accrual. Further investigation is needed to reveal the underlying causes.