Relationship between pediatric adiposity and cardiovascular risk factors in Saudi children and adolescents.

BACKGROUND: The etiology of childhood obesity is growing at alarming rates in developed and developing countries. The aim of the present study was to investigate the prevalence of cardiovascular risk factors (hypertension, dyslipidemia, and hyperglycemia) in a sample of Saudi children and to assess their association with different measures of body adiposity. METHODS: A cross-sectional study was conducted of 200 Saudi children, who were randomly selected from the pediatric clinics at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Anthropometric variables were measured for all study subjects. Fasting blood samples were collected for measurement of blood glucose, insulin, and lipid profile. RESULTS: Almost half of the study population was overweight and one tenth was obese according to body mass index levels, irrespective of sex. The prevalence of central obesity was higher using the waist-height ratio as opposed to waist circumference and this was true for both sexes. Significantly higher means levels of glucose, insulin, and lipids (P<0.0001 in all) were seen among overweight and obese children than their lean counterparts. All obesity measures in children were significantly associated with cardiovascular risk factors. CONCLUSION: The severity of overall and abdominal obesity in Saudi children is associated with a higher prevalence of cardiovascular risk factors, with the relationship strength varying by sex.

Dietary intake of fatty acids and antioxidants in relation to radiographic knee osteoarthritis: results from a case-control study.

BACKGROUND: The present study aimed to investigate levels of nutrient intakes, including dietary antioxidant quality (DAQ) score, among Saudi females with and without knee osteoarthritis (OA). We also aimed to examine the relationship between nutrient intakes and knee OA severity. METHODS: One hundred female participants with symptomatic primary knee OA were matched for age with 100 apparently healthy females and were sequentially recruited from the Orthopaedics Department, Faculty of Medicine, King Abdulaziz University Hospital, Saudi Arabia, in a case-control study design. Radiographic disease severity of OA was assessed by the Kellgren-Lawrence grading system. Symptomatic severity was evaluated according to the Western Ontario McMaster University Osteoarthritis scores. Dietary intake was assessed using a prevalidated food frequency questionnaire. The DAQ score was calculated considering the risk of an inadequate intake (<2/3 reference nutrient intake) for selenium, zinc, vitamins A, C and E. RESULTS: A higher intake of saturated fatty acids [15.4 (0.3) as a mean (SD) percentage of energy supplied] and monounsaturated fatty acids [16.6 (0.2) as a percentage of energy supplied] than the recommendations was evident among the study population. OA patients consume less antioxidants than non-OA subjects as determined by their DAQ score [8.41 (0.1) versus 9.17 (0.1), P < 0.0001]. After adjusting for potential confounders, DAQ score, and monounsaturated and polyunsaturated fatty acids, most of the micronutrient intakes were found to be negatively associated with the prevalence of radiographic knee OA. CONCLUSIONS: Dietary antioxidants could be implicated in the development and progression of knee OA. Modifying dietary fatty acids may be one way of reducing the development and subsequent burden of knee OA.

Changes in serum lipids of mice experimentally infected with Schistosoma mansoni.

Serum samples of mice infected with 80 cercariae of Schistosoma mansoni for different time periods (2-20 weeks) were used in this study. It was observed that the concentrations of serum total cholesterol and triacylglycerol decreased significantly (P < 0.001, P < 0.0001 respectively) in infected as compared to control mice starting from the fourth week post infection. Similarly, the concentration of serum high density lipoprotein-cholesterol (HDL-C) decreased significantly (P > 0.001) in infected as compared to control mice. However, the serum lipoproteins profile was variable at different stages of infection. On the other hand, the liver weight increased significantly (P < 0.0001) in infected as compared to control mice starting from the sixth week post infection. These changes might be attributed to several metabolites released by S. mansoni which affect the host hepatic tissue resulting in decreased synthesis of these parameters and their release into the circulation.

The effect of Schistosoma mansoni infection on testicular lipid in mice.

This study was performed to establish the changes in the level of some serum hormones (Follicle stimulating hormone "FSH", Leutinizing hormone "LH" and testosterone) as well as to determine the changes in the concentrations of some testicular lipid parameters (viz., total cholesterol and total triacylglycerols) of infected mice with Schistosoma mansoni for different periods of time. Electron microscopical studies were also performed to define any histological changes in the testis upon infection with S. mansoni. The serum levels of gonadotropins (FSH, LH) showed no significant changes in infected as compared to control mice. On the other hand, the serum level of testosterone showed a significant decrease (P < 0.001) in infected as compared to control mice starting form the 14th week post infection. Testicular lipids showed a significant increase (P < 0.01) in the concentration of total cholesterol and a significant decrease (P < 0.005) in the concentration of total triacylglycerols in infected as compared to control mice especially at late stages on infection (14-20 weeks post infection). However, electron microscopical studies showed non significant histological changes in the testicular tissues of infected mice at different stages of infection. It is concluded that schistosomiasis has an important metabolic effect on testicular lipids as well as on the serum level of testosterone, whereas structural changes and spermatogenesis might require a longer period of infection and/or severe infection with higher number of cercariae.

Effect of vitamins C and E intake on plasma lipid concentrations in rats.

Changes in the plasma lipid levels were investigated among rats fed an atherosclerotic-promoting diet containing 0.5% cholesterol and rats fed the same diet with added vitamin C (ascorbic acid), vitamin E (a-tocopherol) and vitamins C + E from one to seven weeks. Total cholesterol (TC) and triglycerides (TG) were significantly increased in rats fed a hyperlipidemic diet from the third week to the seventh week, whereas high density lipoprotein cholesterol (HDL-C) was not affected. Rats supplemented with 5 mg vitamin C, 5 mg vitamin E or 5 mg vitamin C + 5 mg vitamin E per day for four to seven weeks showed significant decrease in the concentration of TC and TG. HDL-C was only affected at the seventh week with vitamin C alone, whereas it was significantly increased with vitamin E alone and vitamins C + E at five to seven weeks. However, supplementation of vitamins C, E or C + E for less than four weeks has no significant effect on plasma lipid concentrations. The antioxidant effect of vitamins C and E is probably a time-dependent process that significantly lowers plasma lipids between week four and week seven following administration of these vitamins. It is therefore suggested that the incidence of coronary heart disease (CHD) may be reduced in lowering plasma lipid levels by dietary supplementation of vitamins C or E.

Effect of dantrolene pretreatment on heat stroke in sheep.

Dantrolene is effective in the management of malignant hyperpyrexia. Due to the similarities of malignant hyperpyrexia and heat stroke, we have investigated the effect of dantrolene on heat stroke in sheep. Our study indicates that dantrolene pretreatment decreases the extent of heat stroke signs and some of the induced changes in enzymes and hormones. These results indicate that dantrolene may be a valuable drug in the prophylaxis against heat stroke attack in susceptible individuals.

Level of serum fructosamine in Saudi diabetic patients.

Fructosamine, a compound used to measure serum glycosylated proteins was assayed in 105 Saudi diabetic subjects and 54 healthy non-diabetic Saudi subjects. Fructosamine concentrations in diabetics were significantly higher than in healthy controls (p less than 0.0005). Fructosamine concentrations correlated significantly with fasting blood glucose and HbA1 in diabetics (r = 0.677, p less than 0.0005, and r = 0.598, p less than 0.0005, respectively). The correlation between fructosamine and HbA1 was significant in the oral hypoglycemic-treated diabetics and poor in the insulin-treated diabetic group (r = 0.568, p less than 0.0005, and r = 0.526, p = 0.01). Fructosamine concentrations correlated poorly with the duration of diabetes (r = 0.221, p less than 0.05).

Tympanic thermometry in heat stroke: is it justifiable?

Heat stroke is a medical emergency. Quick diagnosis, and sorting of victims for severity is very important for positive prognosis. Tympanic membrane thermometry was introduced as a good index for core body temperature. Therefore, we have used a sheep model for heat stroke, to study the reliability of measuring body temperature at the tympanic membrane, as a diagnostic index in heat stroke management. This was compared to measuring body temperature at the skin and the rectum. We have observed no major superiority of tympanic over rectal thermometry in regard to its ability to sort out heat stroke cases according to severity. On the other hand, skin thermometry was found not to be a reliable index in this regard.

Fatty acid profiles of sebaceous triglycerides by capillary gas chromatography with mass-selective detection.

Fatty acid methyl esters prepared from the triglyceride fraction of skin surface lipids from six adult human males were chromatographed on a 50-m fused-silica column coated with the highly polar cyanopropylpolysiloxane phase. This permitted the resolution of double-bond positional and geometric isomers. By means of mass-selective detection, 33 saturated and 14 unsaturated fatty acid chain types were analysed. Interpretation of the mass spectra combined with precise calculation of equivalent chain length values permitted the identification of 22 saturated and all of the unsaturated chain types. Quantification by integration of total-ion and selected-ion chromatograms revealed marked variation in the triglyceride fatty acid composition between different subjects. The greatest variation was observed in the concentrations of even-carbon-numbered iso-branched acids, which ranged from 1.5 to 11% of the saturated and from 1.9 to 12.7% of the monounsaturated acids. The anteiso chain structures constituted 4-9% of the saturated and 3-6% of the unsaturated members. Fatty acids with 4-methyl branch showed the least variation, in the range 5.7-7.4%. Other methyl-branched acids made up 4-10% of the saturated group, but were not detected in the unsaturated acids fraction. Two 18:1 fatty acids were identified (a delta 8 and a delta 9), which possibly have different anatomical origins. Similarly, two 18:2 fatty acids (linoleic and a 2,3-dimethyl derivative) were identified. A 2-methyl C17 acid, probably of bacterial origin, was detected.

Effect of hypophysectomy and hormone replacement on fatty elongation in isolated microsomes of rat testes.

Effect of hypophysectomy on fatty acid elongation was investigated in isolated rat testicular microsomes incubated with [14C]malonyl CoA. Hypophystectomy resulted in a 40% decrease in total incorporation of 14C into fatty acids of microsomes. Several 18- and 20-carbon fatty acids of testicular microsomes from hypophysectomized rats had less 14C than did those from nonhypophysectomized ones, whereas only docosa-7,10,13,16-tetraenoic acid (22:4w6) had more 14C. Testosterone injected subcutaneously into hypophysectomized rats at a dose of 0.5 mg per day for eight days posthypophysectomy had no apparent effect on either the total 14C incorporated or the distribution of the 14C in the various fatty acids. Daily subcutaneous injections of 50 or 100 micrograms follicle stimulating hormone (FSH) had some effect on both total incorporation and distribution of 14C. Addition of 0.5 mg testosterone to the 50 micrograms FSH gave the same results as the FSH alone. Smaller amounts of stearic acid (18:0) and linoleic acid (18:2) and increased amounts of docosa-4,7,10,13,16-pentaenoic acid (22:5w6) were present in the microsomes of hypophysectomized compared to nonhypophysectomized rats. Testosterone replacement did not affect these differences, but FSH administration was partially effective in altering the values toward those observed in nonhypophysectomized rats. Results obtained in these experiments indicate that there is inhibition of the testicular microsomal fatty acid elongation system in hypophysectomized rats and that, although testosterone is not at all effective in relieving the inhibition, FSH administration is at least partly effective.

Variability in the composition of human skin surface lipids in tropical climates.

Skin surface lipid samples were collected by the hexane sponge technique from the foreheads of 180 male and 131 female Saudi subjects living in the Jeddah-Makkah area (summer temperatures up to 47 degrees C). The lipid samples were analyzed by densitometric thin layer chromatography. Seven major lipid classes were determined. The percentages for squalene, cholesterol esters, wax esters, triglycerides, free fatty acids, cholesterol and diglycerides were determined. When these parameters were compared to the corresponding values reported for subjects living in the much cooler climates of Europe and N. America, most of the values for Saudi females were found very similar to the values of these subjects, while for Saudi males squalene and wax esters were 2.8-5.1% higher and the triglycerides/free fatty acids were 3-5% lower. The possible reasons for the observed variability between both sexes, their relation to European and N. American subjects, as well as the role of hot climates in inducing these variations are discussed.

The effects of hypophysectomy and testosterone treatment on the composition and metabolism of testicular lipids.

The effects of hypophysectomy and of testosterone administration on lipid composition and metabolism of rat testicular tissue have been investigated. Increased concentrations of triacylglycerols and cholesterol were observed in testes of hypophysectomized compared to control (non-hypophysectomized) rats on the eighth day posthypophysectomy. Administration of testosterone maintained the concentrations of these lipids at about normal levels. The concentration of phospholipids was not affected by the hypophysectomy. Incorporation of 14C from 1-[14C] linoleate into testicular lipids was determined 24 hours after intratesticular injection. In hypophysectomized compared to control rats there was more 14C in C 16:0, C 20:2 and C 20:3 and less 14C in C 20:4 and C 22:4 of both phospholipids and triacylglycerols. After intratesticular injection of 1-[14C] eicosatrienoate there was more 14C in C 16:0 and C 20:3 and less 14C in C 20:4 and C 22:4 of both phospholipids and triacylglycerols of hypophysectomized compared to control rats. Intratesticular injection of 1-[14C]-arachidonate resulted in less 14C incorporation in C 22:4 in testes of hypophysectomized than in those of control rats. Treatment with testosterone did not affect the metabolism of any of the 14C-substrates. These results indicate that the testicular desaturation of C 20:3 to arachidonate, requiring a delta 5 desaturase, is inhibited by hypophysectomy and that testosterone by itself may control the concentrations of some testicular lipid classes but not the metabolism of the polyenoic acids.

Effect of essential fatty acid deficiency on lipids of rat Sertoli and germinal cells.

The effect of essential fatty acid deficiency on lipids of separated rat Sertoli and germinal cells was determined at various time intervals after the animals were placed on a fat-free diet. Alterations in the fatty acid composition typical of essential fatty acid deficiency were noted in the Sertoli cells as well as in germinal cells as early as Days 9-14 on the fat-free diet. These changes included increased concentrations of oleic acid (18:1W9)2 and the appearance of 20:3W9. In some of the rats there were also decreases in linoleic (18:2W6) and arachidonic acids ((20:4W6), but no significant differences were found between Sertoli and germinal cells. Feeding a corn oil diet to rats previously maintained on a fat-free diet for 4 weeks reversed the changes in fatty acid composition of both Sertoli and germinal cells at the times studied. Lipid changes in phospholipids closely reflected those observed in the total lipids. These early changes in Sertoli cell lipids caused by an essential fatty acid deficiency may have important consequences since the Sertoli cell lipids caused by an essential fatty acid deficiency may have important consequences since the Sertoli cells play a significant role in the spermatogenic process.