Obesity and upper body fat distribution in Mexican American children from families with a diabetic proband

Upper and centralized body fat distribution is associated with non-insulin dependent diabetes mellitus (NIDDM). Few studies have focused on anthropometric characteristics of preadults from families in which there is a diabetic (NIDDM) proband. This study explores the prevalence of upper and centralized body fatness in Mexican American children from the Diabetes Alert study (1981–1983) in Starr County, Texas. Anthropometric data on 165 males and 224 females 9–19 years include measures of adiposity such as skinfold thicknesses and the body mass index (BMI), a measure of overweight. They show rates of obesity two to three times that of White children of comparable age and sex from National Health Surveys. In comparison with U.S. White subjects, Mexican American adults are shorter, have more adiposity and arm muscle mass and have sitting heights and body breadths at the mean of these dimensions for the U.S. population. Children from Diabetes Alert families show only marginal excess of severe obesity (> 95th percentile of BMI) when compared to the general population of children surveyed in Starr County schools. Girls from these families, but not boys, have excess fatness in the BMI compared to Mexican American children from the Hispanic Health and Nutrition Examination Survey (HHANES); suprailiac skinfold thicknesses are also greater in children of the Diabetes Alert study than in HHANES children. From 1972 through 1982, Mexican American children in South Texas showed an increase in average stature, weight, and the BMI. These data together suggest that excessive obesity exists and may be increasing in children in populations at risk for NIDDM. The prevention of NIDDM in the Mexican American population may be more effective if educational and promotional interventions include the school aged population. © 1993 Wiley-Liss, Inc.     

Decellularization and genipin crosslinking of amniotic membrane suitable for tissue engineering applications

Abstract

Amniotic membrane has the potential to be used as scaffold in various tissue engineering applications. However, increasing its biostability at the same time maintaining its biocompatibility is important to enhance its usage as a scaffold. This studied characteristics genipin-crosslinked amniotic membrane as a bioscaffold. Redundant human amniotic membranes (HAM) divided into native (nAM), decellularized (dAM) and genipin-crosslinked (clAM) groups. The dAM and clAM group were decellularized using thermolysin (TL) and sodium hydroxide (NaOH) solution. Next, clAM group was crosslinked with 0.5% and 1.0% (w/v) genipin. The HAM was then studied for in vitro degradation, percentage of swelling, optical clarity, ultrastructure and mechanical strength. Meanwhile, fibroblasts isolated from nasal turbinates were then seeded onto nAM, dAM and clAM for biocompatibility studies. clAM had the slowest degradation rate and were still morphologically intact after 30 days of incubation in 0.01% collagenase type 1 solution. The dAM had a significantly highest percentage of swelling than other groups (p?<?0.05). Besides, the dAM retained the collagen content at similar level of nAM. Although the dAM had highest mechanical strength compared to the rest of the groups, the differences were statistically insignificant. Cell attachment on dAM and 0.5% clAM was higher compared to that on nAM and 1.0% clAM. In conclusion, clAM have better biostability and biocompatibility compared to the nAM and dAM. Together with other suitable characteristics of the clAM such as percentage of swelling, structural integrity and ECM content, clAM is suitable as scaffold for various tissue engineering applications.     

Variants in CXADR and F2RL1 are associated with blood pressure and obesity in African-Americans in regions identified through admixture mapping

OBJECTIVE:: Genetic variants in 296 genes in regions identified through admixture mapping of hypertension, BMI, and lipids were assessed for association with hypertension, blood pressure (BP), BMI, and high-density lipoprotein cholesterol (HDL-C). METHODS:: This study identified coding SNPs identified from HapMap2 data that were located in genes on chromosomes 5, 6, 8, and 21, wherein ancestry association evidence for hypertension, BMI, or HDL-C was identified in previous admixture mapping studies. Genotyping was performed in 1733 unrelated African-Americans from the National Heart, Lung and Blood Institute's Family Blood Pressure Project, and gene-based association analyses were conducted for hypertension, SBP, DBP, BMI, and HDL-C. A gene score based on the number of minor alleles of each SNP in a gene was created and used for gene-based regression analyses, adjusting for age, age, sex, local marker ancestry, and BMI, as applicable. An individual's African ancestry estimated from 2507 ancestry-informative markers was also adjusted for to eliminate any confounding due to population stratification. RESULTS:: CXADR (rs437470) on chromosome 21 was associated with SBP and DBP with or without adjusting for local ancestry (P?相似文献   

The protective effect of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes

OBJECTIVES:

The aim of this study was to investigate the protective effects of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell (RBC) membrane oxidative stress in rats with streptozotocin-induced diabetes.

METHODS:

Forty male Sprague-Dawley rats weighing 230-250 g were randomly divided into four groups (n = 10 rats each): control group (N), roselle-treated control group, diabetic group, and roselle-treated diabetic group. Roselle was administered by force-feeding with aqueous extracts of roselle (100 mg/kg body weight) for 28 days.

RESULTS:

The results demonstrated that the malondialdehyde levels of the red blood cell membranes in the diabetic group were significantly higher than the levels in the roselle-treated control and roselle-treated diabetic groups. The protein carbonyl level was significantly higher in the roselle-treated diabetic group than in the roselle-treated control group but lower than that in the diabetic group. A significant increase in the red blood cell membrane superoxide dismutase enzyme was found in roselle-treated diabetic rats compared with roselle-treated control rats and diabetic rats. The total protein level of the red blood cell membrane, osmotic fragility, and red blood cell morphology were maintained.

CONCLUSION:

The present study demonstrates that aqueous extracts of roselle possess a protective effect against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes. These data suggest that roselle can be used as a natural antioxidative supplement in the prevention of oxidative damage in diabetic patients.     

Sequence variation within the neuropeptide Y gene and obesity in Mexican Americans

OBJECTIVE: Recently, we reported evidence for linkage between neuropeptide Y (NPY) and both obesity and several obesity-related quantitative measures in a sample of Mexican Americans from Starr County, Texas. The purpose of this study was to investigate putative variation within the coding and promoter regions of NPY. RESEARCH METHODS AND PROCEDURES: Five young, obese individuals (body mass index [BMI] 33 to 45 kg/m2, age 14 to 30 years); five adult, lean individuals (BMI 20 to 26 kg/m2, age 39 to 65 years); and five sibling pairs sharing no alleles that were identical by descent at a marker locus proximal to NPY were selected for fluorescence-based sequencing of approximately 1100 base pairs (bp) immediately 5' from the start site and all four exons of NPY. We identified a total of eight variant sites, including a 2-bp insertion/deletion (I/D) within a putative negative regulatory region (-880I/D) and a 17-bp deletion at the exon 1/intron 1 junction (69I/D). The -880I/D and 69I/D variants were typed in a separate random sample of Mexican Americans (N = 914) from Starr County, Texas. RESULTS: Analyses of variance resulted in a significant association between -880I/D and waist-to-hip ratio (p = 0.041) in the entire sample and between -880I/D and BMI (p = 0.031), abdominal circumference (p = 0.044), and waist-to-hip ratio (p = 0.041) in a non-obese subsample (BMI < 30 kg/m2, n = 594). The 69I/D variant was observed in only one pedigree and does not appear to segregate with obesity within this pedigree. DISCUSSION: This study reports newly identified common human sequence variation within the regulatory and coding sequence of NPY. Several variants were observed, and of those tested, the -880I/D promoter region variant may influence body fat patterning in non-obese individuals but does not appear to play a major role in the etiology of common forms of obesity in this population.     

Genetic bottlenecks, perceived racism, and hypertension risk among African Americans and first-generation African immigrants

The complexity of factors influencing the development of hypertension (HTN) in African Americans has given rise to theories suggesting that genetic changes occurred due to selection pressures/genetic bottleneck effects (ie, constriction of existing genetic variability) over the course of the slave trade. Ninety-nine US-born and 86 African-born health professionals were compared in a cross-sectional survey examining genetic and psychosocial predictors of HTN. We examined the distributions of three genetic loci (G-protein, AGT-235, and ACE I/D) that have been associated with increased HTN risk. There were no significant differences between US-born African Americans and African-born immigrants in the studied genetic loci or biological variables (eg, plasma renin and angiotensin converting enzyme activity), except that the AGT-235 homozygous T genotype was somewhat more frequent among African-born participants than US-born African Americans. Only age, body mass index, and birthplace consistently demonstrated associations with HTN status. Thus, there was no evidence of a genetic bottleneck in the loci studied, ie, that US-born African Americans have different genotype distributions that increase their risk for HTN. In fact, some of the genotypic distributions evidenced lower frequencies of HTN-related alleles among US-born African Americans, providing evidence of European admixture. The consistent finding that birthplace (ie, US vs Africa) was associated with HTN, even though it was not always significant, suggests potential and unmeasured cultural, lifestyle, and environmental differences between African immigrants and US-born African Americans that are protective against HTN.     

Effects of dietary trans-fatty acids on reproductive performance of Wistar rats

1. Wistar rats were fed for three successive generations on a semi-purified diet, in which the fat was provided by butter, sunflower oil, rapeseed oil or hydrogenated vegetable fat, differing in the content of cis,cis-18:2 and trans-18:1 fatty acids. Effects of these fats on the composition of adipose tissue and reproductive performance were studied. Fatty acids were analysed using high-performance liquid chromatography. 2. The fatty acid pattern of adipose tissue was closely related to dietary fat composition and, established in the first generation, did not change significantly in successive generations of rats. 3. Hydrogenated fat adversely affected litter size, sperm morphology and regularity of oestrous cycle, and prolonged the period of gestation in experimental animals. Differences observed between the generations were not significant. 4. Hydrogenated fat decreased the level of serum testosterone in males, but the differences observed in levels of serum progesterone in females were not apparently related to the dietary trans-fatty acids.     

Frequency and effects of apolipoprotein E polymorphism in Mexican-American NIDDM subjects

We typed 254 non-insulin-dependent diabetic (NIDDM) Mexican Americans living in Starr County, Texas, for the three common apolipoprotein E (apoE) alleles. Typing was performed via DNA amplification and Hha I restriction. The allele frequencies (epsilon 2 = 0.041, epsilon 3 = 0.860, epsilon 4 = 0.099) were in Hardy-Weinberg equilibrium (chi 2 = 0.60, df = 3) and did not differ from a random sample from the same population (chi 2 = 0.16, df = 2). Analysis of variance was used to test for mean differences in lipid, lipoprotein, and glucose levels among apoE types. Significant differences among types were detected for low-density lipoprotein cholesterol (LDL-chol; P = 0.042, R2 = 2.6) and beta-lipoprotein cholesterol (P = 0.019, R2 = 3.3) levels. Mean LDL-chol in E2/3 individuals was 2.69 mM, E3/3 was 3.26 mM, and E4/3 was 3.36 mM. Mean beta-lipoprotein cholesterol in E2/3 individuals was 3.05 mM, E3/3 was 3.64 mM, and E4/3 was 3.67 mM. Based on these results, we conclude that the effects of the apoE polymorphism on lipid profiles and glucose levels are the same in NIDDM subjects as in nondiabetic Mexican Americans and other populations. Other studies investigating the role of apoE polymorphism in diabetic subjects have found increased triglyceride levels in individuals possessing an epsilon 2-allele and an increased frequency of the epsilon 2-allele in hyperlipidemic diabetic subjects. We found no significant difference in mean triglyceride levels among genotypes. Possible reasons for this discrepancy are discussed, including DNA- versus protein-typing methods.     

Origins of U.S. Hispanics. Implications for diabetes

The purpose of this article was to characterize the origins of the United States Hispanic population and discuss the implications of these origins in the context of diabetes risk. Particular attention was focused on the genetic origins of the three major U.S. Hispanic groups, i.e., Mexican Americans, Puerto Ricans, and Cubans. The U.S. Census figures provided basic demographic information. Genetic marker data for ancestral populations were taken from a review of the literature and compendia. Genetic marker data for the Puerto Rican and Cuban populations were extracted from the literature. Genetic markers determined on approximately 1000 randomly selected Mexican Americans from Starr County, Texas, were taken as representative of the Mexican-American population. The Hispanic population is the second largest and fastest growing minority in the U.S. Estimates of the Hispanic population in 1988 indicated some 19.4 million residents, of whom 62% were classified as Mexican, 13% as Puerto Rican, and the remaining 25% as Cubans and others. Various lines of evidence can be used to characterize the Hispanic population and its origins. These include ethnohistory, self-assessment of ancestry, surname distributions, speech and cultural characteristics, quantitative traits, and genetic structure. Genetic data were used to estimate the contribution of putative ancestral populations to the contemporary gene pool. For Mexican Americans, 31% of the contemporary gene pool is estimated to be Native American derived, whereas 61 and 8% are Spanish and African derived, respectively. In Puerto Rico, the percentage of contributions of Spanish, Native American, and African admixture to the population are 45, 18, and 37%, respectively. For Cuba, the parallel estimates are 62, 18, and 20%. The high frequency of Native American-derived genes in the contemporary Hispanic population predict a higher frequency of non-insulin-dependent diabetes mellitus (NIDDM) under the assumption that genes are important in NIDDM etiology. Our results are consistent with the finding of the significant role of genes in determining risk.