Mohsen A.F. El-Hazmi

THE PREVALENCE OF OBESITY AND OVERWEIGHT IN 1-18-YEAR-OLD SAUDI CHILDREN

OBJECTIVESnThe aim of this study was to review the prevalence of overweight and obesity in Saudi children with ages ranging up to 18 years.nnnSUBJECTS AND METHODSnThe study was a cross-sectional national epidemiological household survey, and the study group included 12071 children (boys 6281; girls 6420), with ages ranging from 1-18 years. Their height and weight were measured and body mass index (BMI) was calculated. The study group was classified as obese or overweight, using age- and sex-specific cut-off points for BMI for determining overweight and obesity in children.nnnRESULTSnThe overall prevalence of overweight was 10.7% and 12.7% in the boys and girls, respectively, and obesity was 6.0% and 6.74% in the two groups, respectively. The children were grouped according to the province to which they belonged, and prevalence of obesity and overweight were calculated for each province. The highest frequency was in the Eastern Province, while the lowest was in the Southern Province. The children were further grouped into 1-6, 6-12 and 12-18-year-olds and prevalence of obesity and overweight was calculated. In addition, at yearly intervals, the prevalence of obesity and overweight was calculated. Among the boys and girls, the maximum prevalence of obesity was in the 2-3 year-olds. A decrease in prevalence was found in both males and females up to the age group of 8-13 years, and then the prevalence increased again up to the 18 years age.nnnCONCLUSIONnThis epidemiological household survey shows the overweight and obesity trends in Saudi children based on the international sex-specific cut-off points for BMI. It also shows a variable prevalence in different age groups until after 13 years, when the prevalence rate increases.

Haemoglobin Disorders: A Pattern for Thalassaemia and Haemoglobinopathies in Arabia

The mild course of the diseased state of haemoglobinopathies and the thalassaemias in Arabia and the interaction of the genetic abnormality and environmental factors are particularly interesting as the Peninsula exhibits a diverse climate and topography that encourages study of the interactions between various genetic and environmental factors. The present study is aimed at elucidating the incidence and frequency of these genetic abnormalities in various regions of Saudi Arabia. The relationship between haemoglobinopathies, thalassaemia and glucose-6-phosphate dehydrogenase deficiency on the one hand and malaria parasites on the other are elucidated. The results are presented in the light of the environmental factors prevailing in the area.

The Frequency of 14 β-Thalassemia Mutations in the Arab Populations

The β-thalassemias are a heterogeneous group with respect to molecular pathogenesis, and different populations and ethnic groups differ with respect to the predominating mutations. This variable spectrum of β-thalassemia mutations has resulted in extensive studies in each population and ethnic group to identify the major mutations. In this study we investigated the prevalence of 14 mutations in 253 β-thalassemia patients drawn from eight Arab countries (i.e. Jordan, Egypt, Syria, Lebanon, Yemen, and Saudi Arabia), living in Saudi Arabia and attending Ministry of Health hospitals. The mutations investigated included IVS-l-110 (G→A), IVS-ll-1 (G→A), IVS-l-5 (G→C), codon 39 (C→T), IVS-l-1 (G→A), frameshift at codons 8/9 (+G), frameshift at codons 41/42 (-TTCT), codon 15 (TGG→TAG), IVS-l-6 (T→C), frameshift at codon 16 (-C), IVS-ll-745 (C→G), codon 6 (-A), IVS-I, 3′ end (-25 bp), and Cap +1 (A→C). The most frequently encountered mutations were IVS-l-110 and IVS-ll-1 which were identified in the population of ...

Frequency of Glucose-6-phosphate Dehydrogenase, Pyruvate Kinase and Hexokinase Deficiency in the Saudi Population

The frequencies of glucose-6-phosphate dehydrogenase (G-6-PD), pyruvate kinase (PK) and hexokinase (HK) deficiency were determined in different regions of Saudi Arabia. G-6-PD deficiency was found to range from 0.045 to 0.220 for the male and 0.020 to 0.125 for the female population. The highest frequencies were found to exist in the regions which are endemic to malarial parasite and have high frequencies of sickle cell and thalassaemia genes. Partial deficiencies of PK and HK were encountered in each region, however, no case of complete deficiency of these enzymes was identified. Further investigations are in progress to determine the clinical manifestations of enzyme deficiencies in the Saudi population.

Sickle Cell Gene in the Population of Saudi Arabia

A comprehensive screening program was initiated in Saudi Arabia in 1982 to determine the frequency of the sickle cell (Hb S) gene in the different regions of Saudi Arabia. Over a period of 10 years 30,055 samples were collected from 36 areas in the five provinces of Saudi Arabia; these were screened using electrophoretic techniques in alkaline and acid pH for the presence of Hb S in heterozygous and homozygous states. The overall prevalence of Hb AS was 7.36% and Hb SS was 1.06%, giving an Hb S gene frequency of 0.047. The results from the different regions were separated and the prevalence of Hb AS and Hb SS and Hb S gene frequencies were calculated in each province and each region. The prevalence of Hb AS and Hb SS cases ranged from O to 25.88% and O to 5.27%, respectively. No case of Hb AS or Hb SS were identified in certain areas of the central province (Al-Russ, Al-Unaiza, Al-Mesnab and Bkaria) and northern province (Qurayat and Al-Jouf). In the southern province both Hb S homozygotes and heterozygotes were encountered in all regions except Farasan Island. In all other regions the Hb S gene was encountered, but at a variable frequency. Applying Hardy-Weinberg equilibrium it was observed that in the majority of the regions the observed Hb S homozygotes were significantly higher compared to the number expected (p < 0.0001). This was believed to be due to bias as the samples were collected in the hospital. The Hb S gene frequency in the different regions ranged from 0 to 0.17 when the frequency was calculated on the basis of both Hb AS and Hb. SS cases, and 0 to 0.13 if the gene frequency was calculated after eliminating the Hb SS cases. A close correlation was observed between the Hb S gene frequency and malaria endemicity. This study shows that the Hb S gene occurs frequently in several regions of Saudi Arabia and there is an urgent need to implement control and prevention programs to reduce the number of Hb S homozygous cases.

Molecular Defects in Beta-Thalassaemia in the Population of Saudi Arabia

The beta-thalassaemias are a heterogeneous group of inherited disorders caused by mutations in and around the structural gene of the beta-chain of the adult haemoglobin (HbA). Studies at the gene level have identified a large number of beta-thalassaemia gene variations in different populations. These findings have implications for the use of molecular diagnosis for genetic counselling and prenatal detection of the beta-thalassaemias. In our unit, we initiated studies to investigate the molecular defects in beta-thalassaemias in Saudi Arabia using amplification-refractory mutation systems, dot blot analysis and restriction endonuclease analysis, and identified mutations producing beta(+)- and beta zero-thalassaemias. Twenty of the mutations encountered in the Asian, Mediterranean, Chinese and other Arab populations were investigated. The most commonly encountered mutations in Saudi beta-thalassaemia patients were IVS-I-110, IVS-II-1, CD 39, IVS-I-5 and IVS-I 3 end (-25), while frameshifts at CD 8/9, Cap+1 (A-->C) and CD 6 mutations were identified at a low frequency. These mutations account for 84.94% of the total beta-thalassaemia mutations. The remaining 15% remain unknown. This is the first report on the type and nature of mutations in Saudi beta-thalassaemia patients. It presents frequencies of twenty mutations and emphasises the need for further detailed investigations to clarify the whole spectrum of beta-thalassaemia mutations in the Saudi population.

Haemoglobinopathies, Thalassaemias and Enzymopathies in Saudi Arabia: The Present Status

The presence of the sickle cell (Hb S) gene in Saudi Arabia was first reported by Lehmann et al. in 1963 [Nature 198, pp. 492-493]. Later, Hb S, alpha- and beta-thalassaemia, glucose-6-phosphate dehydrogenase deficiency and other enzymopathies were shown to occur at a variable prevalence in different regions of the country. Recent studies using restriction endonucleases have revealed alpha-globin gene arrangement and beta-globin gene polymorphism in the Saudi population. Interactions between abnormal genes are commonly encountered which often influence the clinical manifestations of sickle cell disease. In this paper, we present recent findings and discuss the status of haemoglobinopathies, thalassaemias and enzymopathies in Saudi Arabia.

Delta agent infection in Riyadh, Saudi Arabia

Blood samples from 186 HBsAg-positive Saudis and 42 HBsAg-positive Philippino blood donors were tested for anti-delta using the radioimmunoassay technique. The high prevalence of anti-delta in Saudis with liver disease (32%) contrasted sharply with that in Saudis with illness other than liver disease (13%) and in apparently healthy Saudis (5.4%). Together with the high prevalence of anti-delta in Philippino blood donors (9.5%), these results suggest that foci of endemic delta infection other than Italy probably exist.

Diabetes Mellitus in Children Suffering from β-Thalassaemia

Insulin-dependent diabetes mellitus (IDDM) is a frequent complication in patients with beta-thalassaemia major. It is believed to be a consequence of the damage inflicted by iron overload to the pancreatic beta-cell. Liver disorders and genetic influences seem to be additional predisposing factors to diabetes mellitus in patients with beta-thalassaemia. Ethnic variations are frequently reported on prevalence and complications of diabetes mellitus in the beta-thalassaemia patients. We investigated 50 Saudi children (< 15 years) with beta-thalassaemia major and 50 beta-thalassaemia minor, and age- and sex-matched controls for the prevalence of diabetes mellitus, and its relation to hitherto claimed predisposing factors. Fasting blood glucose, plasma insulin level, liver function tests, plasma ferritin, iron, and transferrin were assessed in each patient and glucose tolerance was evaluated. Results in patients with beta-thalassaemia major were compared with those obtained for beta-thalassaemia minor and the controls. The results showed moderate elevation of ferritin level in the majority of the beta-thalassaemia major despite desferroxamine therapy. Either hyperinsulinaemia or hypoinsulinaemia was encountered in the majority of these patients. The prevalence of diabetes mellitus was 6 per cent compared to 2 per cent in the beta-thalassaemia minor and normal children. Impaired glucose tolerance (IGT) occurred at a significantly higher (24 per cent) frequency in the beta-thalassaemia major compared to 2 and 0 per cent in the beta-thalassaemia minor patients and normal controls, respectively. The prevalence of diabetes mellitus was significantly lower in the Saudi thalassaemic patients compared to the results obtained from patients of other ethnic groups reported in literature.(ABSTRACT TRUNCATED AT 250 WORDS)

Beta-globin gene haplotypes in the Saudi sickle cell anaemia patients.

The beta S-globin gene haplotypes were investigated using restriction endonucleases Hinc II and Hind III in 22 sickle cell anaemia patients from the eastern province, 67 sickle cell anaemia patients from the south-western province and 4 sickle cell anaemia patients from north-western province. The beta S was found to be mainly linked to the haplotype + + - + + in the eastern province (50% homozygous and 45.45% heterozygous), and - - - - + haplotypes in the south-western (44.77% homozygous and 43.28% heterozygous) and north-western (100% homozygous) provinces. A comparison of the haematological values and clinical manifestations in patients with the two major haplotypes revealed significant differences, with the disease presenting more severely in the south-western compared to the eastern population. The level of Hb F was not significantly different in the two groups and no association could be demonstrated between the beta-globin gene haplotype and Hb F level. These results have led us to suggest that the haplotype + + - + + is in some way linked to a benign sickle cell anemia, though the exact mechanism leading to a benign disease is not clear.