Healthy Saudis Research Articles

High prevalence of CYP2D6*41 (G2988A) allele in Saudi Arabians

The main objective of this study was to evaluate CYP2D6 genetic polymorphism in a Saudi Arabian population by determining the frequencies of CYP2D6*41, CYP2D6*29, CYP2D6*3, CYP2D6*6 and CYP2D6*14 alleles. Genomic DNA was isolated from 192 healthy Saudis representing different geographical regions, and genotyping of the selected CYP2D6 variants was carried out by direct sequencing. The allelic frequency of CYP2D6*41 was found to be 18.4%, and that of CYP2D6*29 to be 2.9%. The other investigated alleles were either not detected or rarely present in the study population. In addition, two commonly shared single nucleotide polymorphisms (SNPs) and two very rare SNPs among CYP2D6 alleles were detected. Further studies are therefore, required to evaluate the metabolic and clinical relevance of CYP2D6*41 in Saudi Arabians.

Effect of Non-Pharmacologic Vitamin D Status Correction on Circulating Bone Markers in Healthy Overweight and Obese Saudis

While moderate to severe vitamin D deficiency is prevalent in Saudi Arabia, skeletal effects associated with this deficiency are not common in this population. In this interventional study we measured the effects of improving vitamin D status on bone biochemical markers in overweight and obese adult Saudis. A total of 47 volunteers (21 males, 26 females) out of the initial 95 subjects were given verbal advice to expose themselves to sunlight for 5–30 min twice weekly and were encouraged to increase their intake of vitamin D–rich foods. Serum 25(OH)D, osteocalcin, and type 1 collagen cross-linked C-telopeptide (CTx), were measured at baseline and after one year. A significant decrease in the prevalence of vitamin D deficiency was observed (44% to 27%) after one year follow-up (p = 0.025). Also, a parallel significant increase in osteocalcin and a decrease in CTX and osteoprotegerin were observed. The results suggest that a modest increase in vitamin D levels among overweight and obese subjects through the promotion of lifestyle changes for one year have marginal effects in bone turnover markers as well as obesity itself.

Cytokine gene polymorphisms of TNFα, IL-6, IL-10, TGFβ and IFNγ in the Saudi population

Studies have demonstrated associations between cytokine gene polymorphisms and ethnicity. In the present work the authors examine polymorphisms in the genes encoding interleukin-6 (IL-6), IL-10, interferon-γ (IFNγ), tumour necrosis factor-α (TNFα) and transforming growth factor-(TGFβ1) using the polymerase chain reaction sequence-specific primer (PCR-SSP) method in 150 healthy unrelated Saudis, and results compared with those from other studied populations. The genotype distributions were consistent with the Hardy-Weinberg equilibrium, and the genotype frequencies observed among Saudis showed both similarity and difference to other populations. The most notable difference was in the distribution of IL-6, where the Saudi population showed a lower CG genotype frequency compared with White American (22% vs. 39.2%, P=0.004), Italian (22% vs. 50%, P<0.0001) and Brazilian (22% vs. 40.8%, P<0.0001) populations. The study population also showed a higher frequency of the IL-6 GG genotype compared with White Americans (72% vs. 45.1%, P<0.0001), Italians (72% vs. 41%, P<0.0001) and Brazilians (72% vs. 49.3%, P<0.0001). These results may have significant clinical relevance to the understanding of prevalent diseases in Saudi Arabia.

152-P

Aim We have recently established a cord blood bank at KAIMRCaiming to use these units for stem cell transplantation at our center and worldwide. Our aim was to investigate the frequency of HLA alleles in cord blood units collected at KAIMRC and to compare them with the HLA frequency from normal healthy Saudis. Methods Blood was collected from cord blood units from consented mothers and DNA was extracted. HLA types were determined using the polymerase chain reaction sequence-specific oligonucleotide (PCR-SSP)method for previously typed healthy controls and by Luminex SSO technology for 163 cord blood units. All samples were typed for HLA-A, HLA-B and HLA-DRB1. Results The most frequent HLA alleles in both cord blood units and healthy control subjects were HLA-A ∗ 02, HLA-B ∗ 50, HLA-B ∗ 51, HLA-DRB1 ∗ 04 HLA-DRB1 ∗ 07 and HLA-DRB1 ∗ 13. High resolution HLA-DRB1 typing results revealed that DBB1 ∗ 07 was of limited polymorphism all individuals were HLA-DRB1 ∗ 07:01 while for DRB1 ∗ 04 and DRB1 ∗ 13 many alleles were detected including HLA-DRB1 ∗ 04:01⧹02⧹05⧹06⧹13⧹30⧹36⧹59 and HLA-DRB1 ∗ 13:01⧹02⧹03⧹22⧹34⧹39⧹69⧹79⧹96. HLA-DRB1 ∗ 04:05 and HLA-DRB1 ∗ 13:02 were the most common alleles. Conclusions Our collected cord blood units represent the Saudi population and is a useful source for stem cell transplantation.

Daily intake of selenium and concentrations in blood of residents of Riyadh City, Saudi Arabia

Concentrations of selenium (Se) in food from local markets of Riyadh, Kingdom of Saudi Arabia (KSA) were measured and daily intake calculated based on information from a questionnaire of foods eaten by healthy Saudis. The daily intake of Se was then compared to concentrations of Se in blood serum. Primary sources of Se in the diet of Saudis were as follows: meat and meat products (31%), egg (20.4%), cereals and cereal products (16%), legumes (8.7%), fruits (6.8%), milk and dairy products (2.0%), beverages (2%), sweets (1.8%), pickles (0.2%), and oil (0.02%). Daily intake of Se, estimated to be 93 μg Se/person/day, was slightly greater than that calculated from the Food and Agriculture Organization (FAO) food balance sheet for KSA, which was approximately 90 μg Se/person/day. The daily intake of Se by Saudis in Riyadh was greater than that of Australians or Dutch but less that of Canadians and Americans. There was a statistically significant correlation (R = +0.38, P < 0.05) between daily intake of Se and concentrations of Se in blood serum of Saudis in Riyadh. The mean concentration of Se in serum was 1.0 × 10(2) ± 30.5 μg Se/l. Taken together, the results suggest that the average Se intake and Se serum concentrations are within the known limits and recommendations, making it unlikely that Saudis are on average at risk of deficiency or toxicity.

Influence of vitamin D levels on bone mineral density and osteoporosis

BACKGROUND AND OBJECTIVES:The effects of vitamin D on bone mass remain to be understood. This study was conducted with the objective of evaluating the influence of 25-hydroxyvitamin D (25OHD) levels on bone mineral density (BMD) among Saudi nationals.DESIGN AND SETTING:Cross-sectional study carried out at university hospital from 1 February 2008 to 31 May 2008.SUBJECTS AND METHODS:Healthy Saudi men and women in the peak bone mass (PBM) age group and those aged ≥50 years were recruited from the outpatient department of King Fahd University Hospital, Al Khobar, Saudi Arabia, between February 1, 2008, and May 31, 2008. Patient age and sex were documented, and body mass index was calculated. Hematological, biochemical, and serum 25OHD tests were performed. BMD was determined by dual-energy x-ray absorptiometry of the upper femur and lumbar spine. Patients were divided into three groups, based on their 25OHD level.RESULTS:Data from 400 patients were analyzed. Among individuals with a normal 25OHD level, 50% of women and 7% of men in the PBM age group and 26.4% of women and 49.2% of men aged ≥50 years had low bone mass. In patients with 25OHD insufficiency, 84.2% of women and 88.9% of men in the PBM age group and 83.3% of women and 80% of men aged ≥50 years had low bone mass. Results for patients with 25OHD deficiency revealed that none of the men and women in the PBM age group or ≥50 years old had normal BMD. Significant positive correlations between 25OHD level and BMD and significant negative correlations with parathyroid hormone were shown in most of the groups.CONCLUSIONS:This study showed that the vitamin D level significantly influences BMD reading among Saudi individuals. Evaluation and treatment of hypovitaminosis D should be considered during management of low bone mass.

190-P HLA-B50 polymorphism in healthy Saudis

190-P HLA-B50 polymorphism in healthy Saudis

Gaining Weight During the Lifetime Can Alter Vitamin D Status

In Kingdom of Saudi Arabia, the traditional diet characterized by high fiber content and low fat, however, the diet in the Saudi Arabia has changed dramatically over the last two decades and has become more western fast food, which is lower in vitamin, and mineral, this unbalance diet can lead to obesity. Obesity is one of the major problems in Saudi Arabia, especially among women.Gaining weight since 18 years and became Obese in later life usually have inadequate vitamin D status due to the decrease vitamin D bioavailability from the cutaneous. In this study we examine whether the current and weight at 18 years can alter vitamin D status among a healthy Saudis' women. The participants were recruited as they presented their regular clinical check‐ups, and their blood was drawn. Their ages ranged between 20 and 75 years, the bio‐samples were taken from June 2009 through August 2009 (n=120). We hypothesized that women who maintained stable weight over time had a higher circulating of 25‐dihydroxyvitamin D3 (25(OH)2D3) compared to those who gained weight. The result: Women who gain weight during their lifetime have low vitamin D level compared to that maintains stable weight.

Evaluation of Vitamin B6 Status of Adult Saudis in Al-Qassim Region-Saudi Arabia

The aim of this study was to evaluate vitamin B status of adult Saudis in Al-Qassim region-Saudi 6 Arabia. A sample of 239 (127 males and 112 females) healthy Saudi adults was recruited. Vitamin B status 6 was evaluated by dietary intake and biochemical measurements. Results of dietary intake measurements showed that means of vitamin B intake and intake of vitamin B to protein ratio for males and females were 6 6 1.97±0.58 mg/day, 0.021±0.003 and 1.89±0.61 mg/day, 0.020±0.04, respectively. Results of biochemica l measurements showed that means of plasma pyridoxal phosphate (PLP) concentration and average urinary 4-Pyridoxic Acid (4-PA) excretion for males and females were 29.6±9.6 nmol L and 7.0±2.4 µmol day and -1 -1 31.7±10.4 nmol L and 6.8±2.5 µmol day , respectively. The study also investigated and discussed other -1 -1 health indicators that are related to vitamin B status including Body Mass Index (BMI), plasma albumin 6 concentration and alkaline phosphatase activity. Results of dietary intakes and biochemical measurements indicated an adequate status of vitamin B. There were no significant differences between males and 6 females in any of the previous measurements. This study indicated an adequate status of vitamin B among 6 healthy adult Saudis in Al-Qassim region, however due to the numerous functions and the importance of the vitamin, the study suggested a further evaluation in various groups of the Saudi population in other regions of the country.

Association of HLA loci alleles and antigens in Saudi patients with vitiligo

HLA complex is composed of several closely linked loci, each containing several alleles, yielding a high expression of polymorphism. Vitiligo, a commonly acquired dermatological disorder, has been associated with different HLA antigens in different ethnic groups. In this study, HLA classes I (HLA-A, B, and C) and II (HLA-DR, DQ) antigens/alleles were analyzed in a group of 80 Saudi subjects consisting of vitiligo patients (40) and matched controls (40). The frequency of antigens of various HLA loci was tested using two-stage microcytotoxicity assays, while the frequency of alleles of HLA-DR was screened by polymerase chain reaction/sequence specific primers (PCR/SSP) method. The frequencies of HLA-B7, B15, Bw6, Cw6, Cw7, and DRB4*010101 were found to be significantly higher in vitiligo patients compared to controls [P = 0.029, 0.015, 0.033, 0.009, 0.043, and 0.015, respectively, with relative risk (RR) > or = 3, etiologic fraction (EF) > or = 0.4]. On the other hand, HLA-A9, B5, DQ1, and DRB3*010101 were significantly decreased in vitiligo patients compared to healthy Saudis [P = 0.008, 0.004, 0.028, and 0.04, respectively, with RR < 1 and preventive fraction (PF) < 0.5]. Among the patients, the highest allele frequency was noted for DRB4*010101(70%), while in controls it was for DRB3*010101 (72.5%). These results for antigens and allele frequency of various HLA Loci in vitiligo patients and control subjects suggested that HLA-B7, Bw6, Cw6, Cw7, and DRB4*010101 could be susceptible to vitiligo, while HLA-A9, B5, DQ1, and DRB3*010101 might be negatively associated with the development of vitiligo in Saudis.

Bone mineral density of the spine and femur in healthy Saudis.

The reference values of bone mineral density (BMD) were determined in healthy Saudis of both sexes and compared with US / northern European and other reference data. BMD was determined by dual-energy X-ray absorptiometry (DXA) at the lumbar spine and femur including subregions: trochanter, Ward's triangle, and neck, in 1,980 randomly selected Saudis (age range 20-79 years; 915 males and 1,065 females) living in the Jeddah area. Age-related changes in BMD were similar to those described in US / northern European and Lebanese reference data. Decreases in BMD of males were evident (% per year): 0.3-0.8 (lumbar spine), 0.2-0.4 (femoral trochanter), 0.2-1.4 (Ward's triangle), and 0.2-0.7 (femoral neck). Also, decreases in BMD of females were observed (% per year): 0.8-0.9 (lumbar spine), 0.7-0.9 (Ward's triangle), and 0.3-0.7 (femoral neck). Using stepwise multiple regressions that included both body weight and height, the former had 2-4 times greater effect on BMD than the latter. Using the mean BMD of the <35-year-old group the T-score values were calculated for Saudis. The prevalence of osteoporosis in Saudis (50-79 years) at the lumbar spine using the manufacturer's vs Saudi reference data was 38.3-47.7% vs 30.5-49.6 (P<0.000), respectively. Similarly, based on BMD of total femur, the prevalence of osteoporosis using the manufacturer's vs Saudi reference data was 6.3-7.8% vs 1.2-4.7% (P<0.000), respectively. Saudis (> or =50 years) in the lowest quartile of body weight exhibited higher prevalence of osteoporosis (25.6% in females and 15.5% in males) as compared to that of the highest quartiles (0.0% in females and 0.8% in males). The present study underscores the importance of using population-specific reference values for BMD measurements to avoid overdiagnosis and/or underdiagnosis of osteoporosis.

Erythrocyte Membrane Proteins in Healthy Saudis and Patients with Hereditary Spherocytosis and Hereditary Elliptocytosis

Little is known about hereditary spherocytosis (HS) and hereditary elliptocytosis (HE) in the native population of Saudi Arabia, even though these conditions are seemingly common. The purpose of this study was to ascertain the protein make-up of the red cell membrane in healthy Saudis and in patients with HS and HE. Eighteen healthy Saudi subjects (13 males and 5 females), 11 patients with HS (6 males and 5 females) and 11 patients with HE (7 males and 4 females) were studied. All normal controls and patients underwent SDS-PAGE red cell membrane protein analysis in duplicate and the stained protein bands were identified and quantitated by densitometry. In normal, healthy Saudis, the mean values for seven membrane proteins ( I+/- spectrin, I(2) spectrin, ankyrin, band 3, protein 4.1, protein 4.2, and actin) were similar to those published for normal, healthy Americans. Of the eleven cases with HS, 7 (64%) demonstrated detectable protein abnormalities while 4 (36%) were apparently normal. The electrophoretic patterns of membrane proteins in Saudis with HS differed from those of patients with HS in other parts of the world. Of the 11 cases of HE, 7 (64%) displayed abnormalities while 4 (36%) were normal. The electrophoretic pattern of the main proteins in the membranes of red blood cells in healthy Saudis is similar to that reported from the USA. However, significant differences exist in the electrophoretic patterns between Saudi patients with HS and patients from other parts of the world.

Antipyrine clearance and Metabolite Excretion in Saudi Patients with Non-Alcoholic Chronic Liver Disease

In this report, we examined the hepatic microsomal enzyme activity in 34 Saudi patients with chronic liver disease (CLD) and in 21 healthy Saudi subjects by measuring antipyrine clearance (APCI) and the fraction (%) of antipyrine (AP) dose excreted in urine unchanged (fAP) and in the form of its main metabolites: 3-hydroxymethylantipyrine (fHMAP), norantipyrine(fNORAP), and 4-hydroxyantipyrine (f4OHAP). While APCI, fHMAP, fNORAP, f4OHAP were significantly reduced in patients with CLD, fAP was significantly higher in these patients. Correlation was observed between serum albumin and APCI, fHMAP, fNORAP, or f4OHAP and between each two of the last three variables. We conclude that Saudis with CLD have uniform rather than selective reduction of hepatic microsomal enzyme activity and that serum albumin is a sensitive indicator of this activity.

Establishment of a Normal Reference Range for Adenosine Deaminase in Plasma of Healthy Saudis Using the Continuous Spectrophotometric Method

The level of adenosine deaminase (EC. 3.5.4.4), was estimated in plasma of 389 healthy males and 493 healthy females in order to establish a normal reference range for Saudis. Using the continuous spectrophotometric method, the reference ranges were calculated in two ways using the mean +/- 2 SD and the 2.5th - 97.5th percentile value methods. In both methods of calculation, a slightly higher range was observed for children as compared to adults. The method of 2.5th - 97.5th percentile values brought almost all of our subjects within the recommended range of 11.5 - 25 U/l. In the current study, the normal range for adenosine deaminase totalled 15.0 - 23.2, 14.8 - 23.6, 15.0 - 23.0 and 16.7 - 24.6 U/l for the overall population, all males, females, and children, respectively. The ranges are discussed in the light of significantly different results obtained by the two calculation methods and recommendation of an appropriate method for healthy Saudis, namely the 2.5th - 97.5th percentile values. The choice of the Ellis and Goldberg kinetic continous monitoring method for the estimation of plasma ADA levels in the current investigation is also hereby justified.

Seropositivity to Hepatitis C Virus in Saudi Haemodialysis Patients

Seropositivity to hepatitis B, C and D viruses was studied in 66 Saudi haemodialysis patients from Al Baha region, south of Saudi Arabia, and was compared to that in 380 healthy Saudis from the same region. The results showed that HCV is endemic in this region (3.6%) and the prevalence of anti-HCV in the haemodialysis patients was 45.5%, which is the highest reported so far in this group of patients. Anti-HCV was related to the amount of blood transfused (>5 units) and the duration of dialysis (>3 years). The region is also hyperendemic for hepatitis B virus (67.4% overall exposure rate in controls compared to 75.7% in haemodialysis patients) and hepatitis D virus (HDV; 11.4% in controls compared to 12.5% in haemodialysis patients). The similarity in profile of HBV markers and HDV between haemodialysis patients and controls indicates that the current strategy regarding HBV is quite effective, in preventing the transmission of HBV and hence HDV but not HCV in haemodialysis patients. A strategy for preventing HCV is recommended.

Prevalence of Primary Adult Lactose Malabsorption in the Eastern Province of Saudi Arabia

Although it has been reported that adult lactose malabsorption (ALM) is relatively common among Arabs, data on the prevalence of ALM in the Saudi and Yemeni populations are scant. We have determine...

Coagulation Parameters in Maternal and Cord Blood at Delivery

A wide range of hemostatic variables were studied in 300 maternal/neonatal pairs at the time of delivery and also in 375 healthy nonpregnant women who served as controls. There was significant prol...

A Study of the Normal Pattern of Platelet Aggregation in Healthy Saudis: A Population-based Study

Platelet aggregation in response to ADP, adrenaline, collagen, arachidonic acid and ristocetin was measured in a large population of healthy Saudi males (n = 393) and females (n = 221) whose age ranged from 11-60 years. The number of observations ranged from 130 for one of the doses of ristocetin (1.0 g/l) to 554 for one of the doses of ADP (2.0 mol/l). Females exhibited more enhanced aggregation responses than males. Blood groups, smoking and body weight had no significant effect on platelet aggregability. No significant variations were noted when morning versus afternoon measurement were compared. The results are discussed and compared to previous reports based on small population studies. The data obtained represent the normal pattern of platelet aggregation in healthy Saudis.

Delta agent infection in Riyadh, Saudi Arabia

Blood samples from 186 HBsAg-positive Saudis and 42 HBsAg-positive Philippine 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 Philippine blood donors (9·5%), these results suggest that foci of endemic delta infection other than Italy probably exist.