Mona Nabulsi

Hypovitaminosis D in healthy schoolchildren.

Background. Vitamin D is essential for skeletal growth, but there are currently no guidelines for vitamin D supplementation after infancy. This study investigates vitamin D insufficiency in healthy children. Methods. Children ages 10 to 16 years from 3 private schools in Beirut, Lebanon, with differing socioeconomic status (SES) were studied: 169 in the spring of 1999 and 177 in the following fall; 83 students participated in both study phases. They had a physical examination, answered a dietary questionnaire, and blood was drawn for calciotropic hormones and indices of bone turnover. Results. Overall, 52% of the students were vitamin D-insufficient; the proportion of insufficiency was 65% in the winter and 40% at the end of the summer. During both seasons, girls had lower vitamin D levels than did boys; those who followed the dress code of covered head, arms, and legs had the lowest levels. Students in the mid-SES school had lower 25-hydroxyvitamin D (25-OHD) levels than did the ones from the high-SES school. After adjusting for confounders, gender, SES, and body mass index remained the significant predictors of vitamin D levels in both seasons (R 2 = 0.53, for spring and 0.28 for fall). There was a significant inverse correlation between 25-OHD levels and parathyroid hormone levels that was best fitted by a curvilinear model (R 2 = 0.19). Conclusion. Even in a sunny country, hypovitaminosis D is common in schoolchildren, more so in the winter. Girls, especially those with a lower SES, are at particular risk. The inverse changes in parathyroid hormone suggest that insufficient vitamin D levels may deleteriously affect skeletal metabolism in healthy adolescents. Vitamin D insufficiency may be prevalent in many other countries where supplementation of milk with vitamin D is not mandatory. Our results call to a reconsideration of vitamin D supplementation in high-risk adolescents to further optimize skeletal health. vitamin D insufficiency, bone metabolism, nutrition, gender, socioeconomic status.

Short- and Long-Term Safety of Weekly High-Dose Vitamin D3 Supplementation in School Children

BACKGROUND Hypovitaminosis D is prevalent in youth worldwide, but the safety of vitamin D at doses exceeding 200 IU/d is unknown in this age group. We assessed the safety of high doses of vitamin D(3) administered to apparently healthy schoolchildren. METHODS To assess short-term safety, 25 subjects randomly received placebo or vitamin D(3) at doses of 14,000 IU/wk for 8 wk. To assess long-term safety, 340 subjects randomly received placebo, vitamin D(3) as 1,400 IU/wk or 14,000 IU/wk for 1 yr. Biochemical variables were monitored at 0, 2, 4, 6, and 8 wk and 8 wk off therapy in the short-term study and at 0, 6, and 12 months in the long-term study. RESULTS In both the short- and long-term studies, mean serum calcium and 1,25-hydroxyvitamin levels did not change in any group. In the short-term study, mean 25-hydroxyvitamin concentrations increased from 44 (+/- 11) to 54 (+/- 19) ng/ml in the treated groups (P = 0.033). In the long-term study, mean 25-hydroxyvitamin D levels increased from 15 +/- 8 to 19 +/- 7 ng/ml (P < 0.0001) in subjects receiving 1,400 IU/wk and from 15 +/- 7 to 36 +/- 22 ng/ml (P < 0.0001) in the group receiving 14,000 IU/wk. No subject developed vitamin D intoxication. CONCLUSION Vitamin D(3) at doses equivalent to 2000 IU/d for 1 yr is safe in adolescents and results in desirable vitamin D levels.

Low calcium and vitamin D intake in healthy children and adolescents and their correlates.

Background: Optimal dietary calcium and possibly vitamin D intake throughout childhood and adolescence may enhance bone mineral accrual. Little data on the intake of these nutrients in Mediterranean countries exist, and predictors of their suboptimal intake are not well defined.Objective: To evaluate systematically the effect of gender, lifestyle factors, and socioeconomic status on mean calcium and vitamin D intake in healthy school children and adolescents from Lebanon.Design: A total of 385 students aged 10–16 y were selected from four public and four private schools between Fall 1999 and Spring 2000. Information on calcium and vitamin D intake, through a semiquantitative food frequency questionnaire that was validated against a 7-day daily record, and on socioeconomic and lifestyle factors were obtained.Results: Only 12% of the students met the adequate intake (AI) recommendation of 1300 mg of calcium/day, and only 16% met the AI recommendation of 200 IU of vitamin D/day. Boys had a significantly higher mean daily calcium intake than girls. Socioeconomic status as assessed by childrens pocket money was a predictor of higher calcium and vitamin D intake. Eating breakfast and physical activity were other correlates of daily calcium and vitamin D intake.Conclusions: Only a minority of students in our study met the AI for calcium and vitamin D. Gender, lifestyle factors, and socioeconomic status were significant predictors of calcium and vitamin D intake. Our findings have important implications regarding the institution of dietary public health strategies to promote skeletal health in Mediterranean countries during a critical time for bone mass accrual.

Effect of gender, puberty, and vitamin D status on biochemical markers of bone remodedeling

Peak bone mass, a determinant of osteoporosis at older ages, is affected by genetic, nutritional, lifestyle, and hormonal factors. Adolescence is a critical time for peak bone mass accrual, and boys achieve a higher peak bone mass than girls. We have reported vitamin D insufficiency in adolescents in our population, but its impact on bone remodeling is unclear. We systematically evaluated the impact of puberty, gender, and vitamin D status on biochemical markers of bone remodeling. Serum osteocalcin (OC), bone alkaline phosphatase (BAP), C-terminal telopeptide of type I collagen crosslinks (S-CTX), and 25 OH vitamin D were measured in 172 healthy students from private schools in the fall of 1999: There were 92 girls and 80 boys, age 10-17 years. In girls, all markers of bone turnover changed significantly with pubertal stage, were maximal at midpuberty, and decreased toward adult levels by Tanner stage V. Conversely in boys, these markers increased during early pubertal stages but had not normalized by Tanner stage V. Levels of all biochemical markers were significantly higher in boys compared to girls even after adjustment for age, body weight, and Tanner stage, P < 0.0001. In the subgroup of girls, those with vitamin D insufficiency, serum levels of BAP and S-CTX were highest. However, in multiple regression analyses, gender was the only consistent correlate of all three markers of bone remodeling. In conclusion, after adjusting for age, weight, and Tanner stages, changes in bone remodeling markers were most powerfully affected by gender. The latter may have important implications on gender differences in peak bone mass.

Vitamin D receptor gene polymorphisms modulate the skeletal response to vitamin D supplementation in healthy girls

OBJECTIVES Vitamin D receptor (VDR) gene plays an important role in bone mass regulation. We have previously shown a beneficial effect of vitamin D supplementation on bone mass in girls. This study investigated whether the musculo-skeletal response to Vitamin D was modulated by polymorphisms in VDR gene. DESIGN Randomized placebo-controlled trial. METHODS 179 girls (10-17 years), were randomly assigned to placebo or Vitamin D3 for one year. VDR genotypes were determined in 167 girls using BsmI, TaqI and ApaI restriction enzymes. Bone mass at the spine, hip, forearm and total body, and lean mass were measured by DXA at baseline and at one year. RESULTS After one year, VDR gene polymorphisms using Bsm1 and TaqI restriction enzymes were associated with percent changes in bone area, BMC and BMD at multiple skeletal sites in the Vitamin D3 group but not in the placebo group. The least increments were observed in the BB and tt genotypes. No similar effect was observed with ApaI enzyme. This relationship between VDR genotypes and changes in BMD and BMC remained significant after adjustment for puberty, changes in lean mass, height and bone area. CONCLUSION VDR gene polymorphisms influence the skeletal response to vitamin D supplementation in healthy adolescent girls.

Alternating ibuprofen and acetaminophen in the treatment of febrile children: A pilot study [ISRCTN30487061]

BackgroundAlternating ibuprofen and acetaminophen for the treatment of febrile children is a prevalent practice among physicians and parents, despite the lack of evidence on effectiveness or safety. This randomized, double-blind and placebo-controlled clinical trial aims at comparing the antipyretic effectiveness and safety of a single administration of alternating ibuprofen and acetaminophen doses to that of ibuprofen mono-therapy in febrile children.MethodsSeventy febrile children were randomly allocated to receive either a single oral dose of 10 mg/kg ibuprofen and 15 mg/kg oral acetaminophen after 4 hours, or a similar dose of ibuprofen and placebo at 4 hours. Rectal temperature was measured at baseline, 4, 5, 6, 7 and 8 hours later. Endpoints included proportions of afebrile children at 6, 7 and 8 hours, maximum decline in temperature, time to recurrence of fever, and change in temperature from baseline at each time point. Intent-to-treat analysis was planned with statistical significance set at P < 0.05.ResultsA higher proportion of subjects in the intervention group (83.3%) became afebrile at 6 hours than in the control group (57.6%); P = 0.018. This difference was accentuated at 7 and 8 hours (P < 0.001) with a significantly longer time to recurrence of fever in the intervention group (mean ± SD of 7.4 ± 1.3 versus 5.7 ± 2.2 hours), P < 0.001. Odds ratios (95%CI) for defervescence were 5.6 (1.3; 23.8), 19.5 (3.5; 108.9) and 15.3 (3.4; 68.3) at 6, 7 and 8 hours respectively. Two-way ANOVA with repeated measures over time revealed a significantly larger decline in temperature in the intervention group at times 7 (P = 0.026) and 8 (P = 0.002) hours.ConclusionA single dose of alternating ibuprofen and acetaminophen appears to be a superior antipyretic regimen than ibuprofen mono-therapy. Further studies are needed to confirm these findings.

Blood Lead Concentrations in 1–3 Year Old Lebanese Children: A Cross-sectional study

BackgroundChildhood lead poisoning has not made the list of national public health priorities in Lebanon. This study aims at identifying the prevalence and risk factors for elevated blood lead concentrations (B-Pb ≥ 100 μg/L) among 1–3 year old children. It also examines the need for universal blood lead screening.MethodsThis is a cross-sectional study of 281 well children, presenting to the pediatric ambulatory services at the American University of Beirut Medical Center in 1997–98. Blood was drawn on participating children for lead analysis and a structured questionnaire was introduced to mothers asking about social, demographic, and residence characteristics, as well as potential risk factors for lead exposure. Children with B-Pb ≥ 100 μg/L were compared to those with B-Pb < 100 μg/L.ResultsMean B-Pb was 66.0 μg/L (median 60.0; range 10–160; standard deviation 26.3) with 39 (14%) children with B-Pb ≥ 100 μg/L. Logistic regression analysis showed that elevated B-Pb was associated with paternal manual jobs (odds ratio [OR]: 4.74), residence being located in high traffic areas (OR: 4.59), summer season (OR: 4.39), using hot tap water for cooking (OR: 3.96), exposure to kohl (OR: 2.40), and living in older buildings (OR: 2.01).ConclusionLead screening should be offered to high-risk children. With the recent ban of leaded gasoline in Lebanon, emphasis should shift to other sources of exposure in children.

Parental attitudes towards and perceptions of their children's participation in clinical research: a developing-country perspective

Background Paediatric clinical research faces unique challenges that compromise optimal recruitment of children into clinical trials. A main barrier to enrolment of children is parental misconceptions about the research process. In developing countries, there is a knowledge gap regarding parental perceptions of and attitudes towards their childrens participation in clinical trials. Objective To explore such perceptions and attitudes in Lebanese parents. Study design 33 in-depth interviews were conducted with parents with and without previous research experience. Interviews were tape-recorded, transcribed in colloquial Arabic, and later subjected to thematic analysis. Results Benefit/risk ratio assessment was a major determinant of parental consent. Fear of adverse events or painful procedures in research was a recurring theme in most interviews. Whereas perception of direct benefit to the child, trust in the physician or institution, financial gains or having a positive previous experience in research facilitated consent, a complex informed consent form and misunderstanding of the term ‘randomisation’ hindered parental approval of participation. Conclusion Lebanese parents have perceptions of and attitudes towards childrens participation in clinical trials that are similar to those reported from the industrialised world. Improving communication with parents and building trust between researchers and parents is important for successful recruitment. Investigators planning to conduct paediatric trials in developing countries need to simplify consent forms and devise new ways to explain randomisation.

Acceptance of prenatal diagnosis for genetic disorders in Lebanon

Acceptance of prenatal diagnosis and termination of pregnancy in the case of an affected fetus may vary from one country to another, depending on the health system, religious belief, cultural and educational backgrounds of the population. Following a previous study on couples at risk for a haemoglobin disorder in Lebanon, we have here interviewed 90 couples at risk for a variety of genetic disorders, in order to assess their acceptance of prenatal diagnosis and the variables that might influence their choice. Overall, 54 per cent of couples said they would request diagnosis in their next pregnancy, while 26 per cent were opposed to such a procedure. In 87.5 per cent of cases, the reason for refusal was because of religious conviction against termination of pregnancy. Refusal of prenatal diagnosis was also related to a lower socio‐economic background and poorer education. Only 12 per cent of couples were properly aware of their genetic risk. Therefore, for prevention of genetic disorders, the emphasis in countries such as Lebanon has probably to be placed on public awareness about genetic risks, the risks of consanguinity, availability of services, while taking into consideration the personal beliefs of the individuals. Copyright

Iron deficiency in young Lebanese children: association with elevated blood lead levels.

Objective To measure the prevalence of transferrin saturation (TS) <12%, and iron-deficiency anemia (IDA) in Lebanese children, and their association with dietary habits, sociodemographic characteristics, and blood lead levels. Procedure A cross-sectional study was performed over a period of 2 years. Of 268 children studied, 142 (53%) were boys and 126 (47%) were girls with an age range of 11 to 75 months. Information collected included nutritional status, blood counts, TS, and blood lead levels. Results The total prevalence of TS<12% and IDA were 33.6% and 20.5%, respectively, and were associated with not having received iron supplements. IDA was more prevalent among males (P=0.04). TS<12% and IDA were significantly associated with elevated blood lead levels in the first age group (11 to 23 mo) (P=0.04, odds ratio=3.19) and (P=0.006, odds ratio=4.59), respectively. Conclusions IDA is common in Lebanese children and is associated with increased blood lead levels, lack of iron supplementation, and cultural dietary habits. Remedial measures such as iron fortification of commonly consumed food are needed on the national level. Lead exposure must be controlled and awareness must be raised about the potentially devastating consequences of combined iron deficiency and lead poisoning on young children.