The relationships between insulin resistance and components of metabolic syndrome in Taiwanese Asians

Interactions of several single nucleotide polymorphisms and high body mass index on serum lipid traits

The interactions between single nucleotide polymorphisms (SNPs) and high body mass index (BMI) on serum lipid profiles are limited. This study was undertaken to detect the interactions of 10 SNPs and high BMI on serum lipid traits in an isolated population. A total of 978 normal BMI (< 24 kg/m2) and 751 high BMI (≥ 24 kg/m2) subjects of Bai Ku Yao were randomly selected from our previous stratified randomized cluster samples. Genotypes of rs2066715, rs1044925, low density lipoprotein receptor (LDL-R) Ava||, rs2070895, rs2000813, rs1801133, rs3757354, rs505151, rs2016520, and rs5888 SNPs were determined by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing. The interactions were detected by factorial design covariance analysis. The genotypic and allelic frequencies of rs2070895 and rs505151 were different between normal and high BMI subjects, the genotypic frequency of rs2000813 and allelic frequency of rs3757354 were also different between normal and high BMI subjects (P < 0.01). The levels of total cholesterol (TC), apolipoprotein (Apo) A1 (rs2066715); TC, low-density lipoprotein cholesterol (LDL-C), ApoA1, ApoB, and ApoA1/ApoB (rs2070895); triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and ApoA1 (rs2000813); TC, HDL-C, LDL-C, ApoA1, and ApoB (rs1801133); HDL-C and ApoA1 (rs3757354) in normal BMI subjects were different among the genotypes (P < 0.01). The levels of LDL-C, ApoB, and ApoA1/ApoB (rs2066715); HDL-C, ApoA1, ApoB, and ApoA1/ApoB (rs2070895); TC, HDL-C, ApoA1, and ApoB (rs2000813); TC, TG, HDL-C, LDL-C, ApoA1, and ApoB (rs1801133); TC, TG, and ApoB (rs3757354); TG (rs505151); TG and ApoA1 and ApoB (rs2016520); and TC, HDL-C, LDL-C, ApoA1, and ApoB (rs5888) in high BMI subjects were also different among the genotypes (P < 0.01). The SNPs of rs2066715 (LDL-C and ApoA1/ApoB); rs2070895 (TC, LDL-C, ApoA1, and ApoB); rs2000813 (ApoB); rs1801133 (TC, TG, and LDL-C); rs3757354 (TC and TG); rs505151 (TG, HDL-C, ApoB, and ApoA1/ApoB); rs2016520 (TG and ApoA1/ApoB); and rs5888 (TG, ApoA1, and ApoB) interacted with high BMI to influence serum lipid levels (P < 0.01). The differences in serum lipid levels between normal and high BMI subjects might partly result from different interactions of several SNPs and high BMI.

Several genetic polymorphisms interact with overweight/obesity to influence serum lipid levels

Background

Information about the interactions of single nucleotide polymorphisms (SNPs) and overweight/obesity on serum lipid profiles is still scarce. The present study was undertaken to detect ten SNPs and their interactions with overweight/obesity on serum lipid levels.

Methods

A total of 978 normal weight and 751 overweight/obese subjects of Bai Ku Yao were randomly selected from our previous stratified randomized cluster samples. Normal weight, overweight and obesity were defined as a body mass index (BMI) < 24, 24–28, and > 28 kg/m²; respectively. Serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) A1 and ApoB levels were measured. Genotyping of ATP-binding cassette transporter A1 (ABCA-1) V825I, acyl-CoA:cholesterol acyltransferase-1 (ACAT-1) rs1044925, low density lipoprotein receptor (LDL-R) AvaII, hepatic lipase gene (LIPC) -250G>A, endothelial lipase gene (LIPG) 584C>T, methylenetetrahydrofolate reductase (MTHFR) 677C>T, the E3 ubiquitin ligase myosin regulatory light chain-interacting protein (MYLIP) rs3757354, proprotein convertase subtilisin-like kexin type 9 (PCSK9) E670G, peroxisome proliferator-activated receptor delta (PPARD) +294T>C, and Scavenger receptor class B type 1 (SCARB1) rs5888 was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing. The interactions were detected by factorial design covariance analysis.

Results

The genotypic and allelic frequencies of LIPC and PCSK9 were different between normal weight and overweight/obese subjects, the genotypic frequency of LIPG and allelic frequency of MYLIP were also different between normal weight and overweight/obese subjects (P < 0.05-0.001). The levels of TC, ApoA1 (ABCA-1); TC, LDL-C, ApoA1, ApoB and ApoA1/ApoB (LIPC); TG, HDL-C, and ApoA1 (LIPG); TC, HDL-C, LDL-C, ApoA1 and ApoB (MTHFR); HDL-C and ApoA1 (MYLIP) in normal weight subjects were different among the genotypes (P < 0.01-0.001). The levels of LDL-C, ApoB and ApoA1/ApoB (ABCA-1); HDL-C, ApoA1, ApoB and ApoA1/ApoB (LIPC); TC, HDL-C, ApoA1 and ApoB (LIPG); TC, TG, HDL-C, LDL-C, ApoA1 and ApoB (MTHFR); TC, TG and ApoB (MYLIP); TG (PCSK9); TG, ApoA1 and ApoB (PPARD); and TC, HDL-C, LDL-C, ApoA1 and ApoB (SCARB1) in overweight/obese subjects were different among the genotypes (P < 0.01-0.001). The SNPs of ABCA-1 (LDL-C and ApoA1/ApoB); LIPC (TC, LDL-C, ApoA1 and ApoB); LIPG (ApoB); MTHFR (TC, TG and LDL-C); MYLIP (TC and TG); PCSK9 (TG, HDL-C, ApoB and ApoA1/ApoB); PPARD (TG and ApoA1/ApoB); and SCARB1 (TG, ApoA1 and ApoB) interacted with overweight/obesity to influence serum lipid levels (P < 0.05-0.001).

Conclusions

The differences in serum lipid levels between normal weight and overweight/obese subjects might partly result from different genetic polymorphisms and the interactions between several SNPs and overweight/obesity.

Metabolic syndrome and renal injury

Both metabolic syndrome (MetS) and chronic kidney disease (CKD) are major global health issues. Current clinical markers used to reflect renal injury include albuminuria and estimated glomerular filtration rate (eGFR). Given the same eGFR level, urine albumin might be a better risk marker to predict progression of CKD and future development of cardiovascular diseases (CVDs). Serum Cystatin C is emerging as a new biomarker for early detection of renal injury associated with MetS and cardiovascular risk. In addition to each component, MetS per se influences the incidence and prognosis of renal injury and the odds ratios increased with the increase in the number of metabolic abnormalities. Hyperinsulinemia, activation of rennin-angiotensin-aldosterone system, increase of oxidative stress, and inflammatory cytokines are proposed to be the plausible biological link between MetS and CKD. Weight control, stick control of blood pressure, glucose, and lipids disorders may lead to lessening renal injury and even the subsequent CVD.

Serum insulin is significantly related to components of the metabolic syndrome in Japanese working men

The aim of this study was to examine the association between serum insulin levels and components of the metabolic syndrome (MS). The target participants were 3054 working men. MS was diagnosed based on the modified criteria of the International Diabetes Federation and was present in 12.9% of the study patients. Serum lipid profiles, uric acid, insulin, plasma glucose, and hemoglobin A1c were measured. Stepwise multiple regression analysis showed that all the components of MS were significantly associated with log-transformed values of the serum insulin. The standardized regression coefficient for the waist circumference was 5-fold higher than that for fasting plasma glucose, being 0.40 and 0.08, respectively. The standardized regression coefficients for diastolic blood pressure, log-transformed values of serum triglyceride, high-density lipoprotein cholesterol, and age were 0.09, 0.13, -0.16, and -0.11, respectively. A statistically significant relationship existed between the components of MS, especially abdominal obesity, and the serum insulin levels.

Prevalence and risk factors of metabolic syndrome in Brazilian and Italian obese adolescents: a comparison study

BACKGROUND

Metabolic syndrome (MS) prevalence between different populations in obese adolescents is scanty to date.

OBJECTIVE

To compare the MS prevalence and related risk factors in Brazilian and Italian obese adolescents.

METHODS

A total of 509 adolescents (110 Brazilian, 399 Italian), aged 15-19 years. Anthropometric characteristics, triglycerides (TG), total, low-density lipoprotein (LDL)-, high-density lipoprotein (HDL)-cholesterol, fasting plasma glucose (FPG), insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and blood pressure were measured.

RESULTS

Age, body mass index (BMI) and BMI z-score were not significantly different between the two subgroups. BMI z-score, TG, FPG, HOMA-IR and systolic blood pressure (SBP) were significantly higher in boys than in girls both in Brazilian and Italian adolescents, while HDL-cholesterol levels were lower in boys than in girls. No significant differences were observed in BMI, LDL and total-cholesterol and DBP in two genders and groups. Insulin, FPG, HOMA-IR and TG were significantly higher, while LDL-cholesterol and SBP were significantly lower in Brazilian than in Italian subjects, both in males and females. HDL and total-cholesterol and diastolic blood pressure (DBP) were not significantly different between the two subgroups and genders. MS prevalence was higher in Brazilian than in Italian obese boys (34.8 vs. 23.6%, p < 0.001) and girls (15.6 vs. 12.5%, p < 0.01). The most frequently altered parameter was HOMA-IR both in subjects with MS (100% in Brazilian and 81.8% in Italian) and without MS (42.9% and 11.7%).

CONCLUSION

Metabolic syndrome represents a worldwide emerging health problem in different ethnical populations, the alterations of the risk factors related to MS (different in their prevalence between different subgroups) being strictly linked to the degree of obesity.

Diagnosis of insulin resistance in hypertensive patients by the metabolic syndrome: AHA vs. IDF definitions

BACKGROUND

Subjects with the metabolic syndrome are accompanied by insulin resistance (IR). However, it is not clear how well the newly defined metabolic syndrome identifies IR specifically in hypertensive subjects.

AIMS

The purpose of the study was to evaluate the performance of the metabolic syndrome, defined by the American Heart Association (AHA) and the International Diabetes Federation (IDF) definitions, in identifying IR in hypertension.

METHODS

The analysis is a cross-sectional study. Totally, 228 hypertensive patients and 92 non-diabetic normotensive controls who received insulin suppressive tests for direct evaluation of their insulin sensitivity were included from the Stanford Asia and Pacific Program for Hypertension and IR. McNemar's tests were used to compare sensitivity and specificity of the AHA-defined with the IDF-defined metabolic syndrome in diagnosis of IR.

RESULTS

The sensitivity of the metabolic syndrome for IR in hypertension was 89.7% and the specificity 45.9% by the AHA definition. Using the IDF definition, the sensitivity was 77.6%, and the specificity increased to 63.5%. The diagnostic power of individual components of the syndrome was also modest. The predictive discrimination of wider waist circumference was similar to that of the AHA-defined metabolic syndrome.

CONCLUSIONS

Use of the metabolic syndrome by the AHA definition provided good sensitivity, but low specificity to diagnose IR in hypertension. The IDF definition improved in false-positive rate, but it was still not specific enough to identify IR in hypertension.

Hyperlipidaemia and its risk factors in the Guangxi Bai Ku Yao and Han populations

OBJECTIVE

To compare the differences in hyperlipidaemia prevalence and its risk factors between the Guangxi Bai Ku Yao and Han populations.

DESIGN

Cross-sectional study of hyperlipidaemia.

SETTING

Both populations were from Lihu and Baxu villages in Nandan County, Guangxi Zhuang Autonomous Region, People's Republic of China.

SUBJECTS

A total of 1170 healthy subjects of Bai Ku Yao and 1173 participants of Han Chinese aged 15-89 years were surveyed by a stratified randomized cluster sampling. Information on demographic, dietary and lifestyle characteristics was collected by standard questionnaires. Blood pressure, height, weight, waist circumference, serum lipids and apolipoproteins were measured, and BMI (kg/m2) was calculated as weight divided by the square of height.

RESULTS

The prevalence rates of hypercholesterolaemia, hypertriacylglycerolaemia and hyperlipidaemia in Bai Ku Yao and Han were 12.4 % v. 26.2 % (P < 0.001), 15.0 % v. 14.8 % (P > 0.05) and 24.4 % v. 33.9 % (P < 0.001), respectively. Hyperlipidaemia was positively correlated with BMI, waist circumference, total energy and total fat intakes, and negatively associated with physical activity and total dietary fibre intake in Bai Ku Yao (P < 0.05 to 0.001). Hyperlipidaemia was positively associated with age, alcohol consumption, BMI, waist circumference, total energy and total fat intakes, and inversely correlated with physical activity and total dietary fibre intake in Han (P < 0.05 to 0.001).

CONCLUSIONS

The prevalence of hypercholesterolaemia and hyperlipidaemia was significantly lower in the Bai Ku Yao than in the Han population, which might result from different dietary habits, lifestyle choices and physical activity level, as well as genetic factors between the two ethnic groups.

Diet, alcohol consumption, and serum lipid levels of the middle-aged and elderly in the Guangxi Bai Ku Yao and Han populations

Bai Ku Yao is an isolated subgroup of the Yao minority in China. The special customs and cultures including their clothing, intraethnic marriages, corn wine and rum intakes are still completely conserved to the present day. Little is known about the association of diet and alcohol consumption with serum lipid levels in this population. The aim of this study was to compare the differences in diet, alcohol consumption, and serum lipid levels of the middle-aged and elderly between the Guangxi Bai Ku Yao and Han populations. A total of 485 subjects of Bai Ku Yao and 501 participants of Han Chinese aged 40 and over were surveyed by a stratified randomized cluster sampling. Information on dietary intake and alcohol consumption was collected by standard questionnaires. Serum lipid levels were measured. Education level, height, weight, body mass index, waist circumference, blood pressure, hypertension, and total energy, fat, protein, dietary cholesterol, and salt intakes were lower in Bai Ku Yao than in Han (P < .05-.001), whereas physical activity level, carbohydrate, vegetal protein, and total dietary fiber intakes were higher in Bai Ku Yao than in Han (P < .001 for all). Serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) A1, and Apo B levels were lower in Bai Ku Yao than in Han (P < .001 for all). The levels of triglyceride, HDL-C, Apo A1, and the ratio of Apo A1 to Apo B in Bai Ku Yao were higher, but the levels of LDL-C and Apo B were lower in drinkers than in nondrinkers. The levels of triglyceride, HDL-C, LDL-C, Apo A1, Apo B, and the ratio of Apo A1 to Apo B in Bai Ku Yao were also influenced by the amount of alcohol consumed (P < .05-.001). High-density lipoprotein cholesterol levels in Han were higher and LDL-C levels were lower in drinkers than in nondrinkers (P < .01 for each). Serum total cholesterol, HDL-C, and LDL-C levels in Han were also associated with the amount of alcohol consumed (P < .05-.001). The differences in the lipid levels between the two ethnic groups may partially attribute to the differences in dietary habits and alcohol consumption.

Comparison of demography, diet, lifestyle, and serum lipid levels between the Guangxi Bai Ku Yao and Han populations

Bai Ku Yao is an isolated subgroup of the Yao minority in China. Little is known about dyslipidemia in this population. The aim of this study was to compare the effects of demography, diet, and lifestyle on serum lipid levels between the Bai Ku Yao and Han populations. A total of 1,170 subjects of Bai Ku Yao and 1,173 subjects of Han Chinese aged 15-89 years were surveyed by a stratified randomized cluster sampling. The levels of total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, apolipoprotein A-I (apoA-I), and apoB were significantly lower in Bai Ku Yao than in Han. Physical activity level and total dietary fiber intake were higher, whereas body mass index (BMI), waist circumference, total energy intake, and total fat intake were lower in Bai Ku Yao than in Han. Hyperlipidemia was positively correlated with BMI, waist circumference, and total energy and total fat intakes and negatively associated with physical activity level and total dietary fiber intake in both populations, but it was positively associated with age and alcohol consumption only in Han. The differences in the lipid profiles between the two ethnic groups were associated with different dietary habits, lifestyle choices, and levels of physical activities.

Prevalence of Hyperlipidemia and Its Risk Factors for the Middle-Aged and Elderly in the Guangxi Hei Yi Zhuang and Han Populations

BACKGROUND

Han is the largest and Zhuang is the second largest among the 56 nationalities in China. Geographically and linguistically, Zhuang can be classified into 43 ethnic subgroups, among which Hei Yi (which means "black worship" and "black dressing") Zhuang is the most conservative group, according to its unique culture and customs. Little is known about the lipid profiles and corresponding risk factors of hyperlipidemia in this population. Therefore, the aim of this study was to compare the effects of demographic characteristics, health-related behaviors, and lifestyle factors on the prevalence of hyperlipidemia for the middle-aged and elderly in the Guangxi Hei Yi Zhuang and Han populations.

METHODS

A sample of 657 people of Hei Yi Zhuang aged 40 years and over was randomly selected from 7 villages in Napo County, Guangxi, China. Information on demographic characteristics, health-related behaviors, and lifestyle factors was collected by questionnaire. Blood pressure, height, weight, waist circumference, and serum lipid and apolipoprotein (apo) levels were measured, and body mass index (BMI) was calculated as a measure of weight relative to height. The results were compared with those in 520 people of Han living in the same region.

RESULTS

The prevalence of hyperlipidemia in the Hei Yi Zhuang was significantly lower than that in the Han (36.2% vs 42.3%; p < .05). The levels of total cholesterol, triglyceride, low-density lipoprotein cholesterol, and apo B in Hei Yi Zhuang were also significantly lower than those in the Han (p < .05 to .001), but the levels of high-density lipoprotein cholesterol and the ratio of apo A-I to apo B in the Hei Yi Zhuang were significantly higher than those in the Han (p < .01 and < .001, respectively). There were no significant differences in apo A-I levels between the two ethnic groups (p > .05). The prevalence of hyperlipidemia was positively correlated with BMI and blood pressure in the Hei Yi Zhuang. Hyperlipidemia was positively associated with age, BMI, and blood pressure and negatively associated with gender (female higher) in the Han.

CONCLUSIONS

In the present study of the middle-aged and elderly population, the Hei Yi Zhuang have a more favorable lipid profile and a lower prevalence of hyperlipidemia than do the Han, and there is also a significant difference in the risk factors for hyperlipidemia between the two ethnic groups, which might result from the effects of different demographic characteristics, health-related behaviors, and lifestyle factors.