Objective. Hypothesising that metabolic syndrome may be associated with or useful in the prediction of pre-eclampsia, we investigated the association between all components of metabolic syndrome and C-reactive protein (CRP) in women with and without pre-eclampsia.Methods. A case–control study was performed. Cases had gestational hypertension or pre-eclampsia and controls were term deliveries. Clinical data and maternal serum was collected. The presence of metabolic syndrome (3/5 variables present) and a metabolic score (continuous 0–5) were investigated. Significant associations were evaluated using t-tests, and Pearson chi-square tests of association. Multivariable logistic regression was used to control for confounders.Results. One-hundred and one cases and 267 controls were evaluated. We observed a higher odds of pre-eclampsia when metabolic syndrome was present (AOR = 2.71 [1.1–6.67], p = 0.03). For every one-unit increase in metabolic score, there was a 39% increased odds of pre-eclampsia (AOR = 1.39 [1.06–1.82], p = 0.017). The odds of pre-eclampsia were nearly four times higher when hs- CRP was >8 (AOR = 3.61 [2.14–6.12], p < 0.001).Conclusions. Metabolic syndrome and hs-CRP are associated with pre-eclampsia. Investigation is crucial to determine if these abnormal lipid and inflammatory pathways observed in women with pre-eclampsia are present pre-pregnancy or develop as a result of the disease process of pre-eclampsia. Further investigation is also warranted to determine whether these abnormalities persist post-pregnancy and if so, their contribution to long-term cardiovascular disease.
Objective— Studies in mice have shown that genetic disruption of monocyte chemotactic protein-1 or its receptor, the C-C chemokine receptor 2 (CCR2), inhibits atherosclerosis, but few data exist in humans to suggest that the monocyte chemotactic protein-1—CCR2 interaction is important in atherogenesis. A common polymorphism in the human CCR2 gene resulting in a substitution of isoleucine for valine (Val64Ile) has been associated with other disease phenotypes in humans. Methods and Results— A cohort of first-degree relatives of persons with premature coronary artery disease was recruited and quantitatively phenotyped for the extent of CAC, a marker of coronary atherosclerosis, by using electron beam CT. The extent of CAC was significantly lower in subjects with the CCR2-Ile64 variant (Val/Ile and Ile/Ile genotypes) than in subjects carrying 2 Val64 alleles, even after adjustment for traditional risk factors. Conclusions— This study provides genetic evidence linking CCR2 with coronary atherosclerosis in humans.
Endothelial lipase (EL), a new member of the lipase family, has been shown to modulate high-density lipoprotein (HDL-C) metabolism and atherosclerosis in mouse models. We hypothesized that EL concentrations would be associated with decreased HDL-C and increased atherosclerosis in humans.Healthy individuals with a family history of premature coronary heart disease (n = 858) were recruited as part of the Study of the Inherited Risk of Atherosclerosis. Blood was drawn in the fasting state before and, in a subgroup (n = 510), after administration of a single dose of intravenous heparin. Plasma lipids were measured enzymatically, lipoprotein subclasses were assessed by nuclear magnetic resonance, and coronary artery calcification (CAC) was quantified by electron beam computed tomography. Plasma EL mass was measured using a newly developed enzyme-linked immunosorbent assay. Median EL mass in pre-heparin plasma was 442 (interquartile range = 324-617) ng/ml. Median post-heparin mass was approximately 3-fold higher, 1,313 (888-1,927) ng/ml. The correlation between pre-heparin EL mass and post-heparin EL mass was 0.46 (p < 0.001). EL mass concentrations in both pre- and post-heparin plasma significantly correlated with all NCEP ATPIII-defined metabolic syndrome factors: waist circumference (r = 0.28 and 0.22, respectively, p < 0.001 for each), blood pressure (r = 0.18 and 0.24, p < 0.001 for each), triglycerides (r = 0.22, p < 0.001; and 0.13, p = 0.004), HDL cholesterol (r = -0.11, p = 0.002; and -0.18, p < 0.001), and fasting glucose (r = 0.11 and 0.16, p = 0.001 for both). EL mass in both routine (odds ratio [OR] = 1.67, p = 0.01) and post-heparin (OR = 2.42, p = 0.003) plasma was associated with CAC as determined by ordinal regression after adjustment for age, gender, waist circumference, vasoactive medications, hormone replacement therapy (women), and established cardiovascular risk factors.We report, to our knowledge for the first time, that human plasma EL concentrations, in both post-heparin and routine pre-heparin plasma, are significantly associated with metabolic syndrome features and with subclinical atherosclerosis. EL may be a pro-atherogenic factor in humans, especially in overweight individuals and those with metabolic syndrome.
The purpose of this research was to evaluate the short-term effects of pioglitazone (PIO) on high-density lipoprotein cholesterol (HDL-C) and other metabolic parameters in nondiabetic patients with metabolic syndrome (MetSyn).Sixty nondiabetic adults with low HDL-C and MetSyn were randomized to PIO or matching placebo for 12 weeks. PIO increased HDL-C by 15% and 14% at 6 and 12 weeks, respectively, compared with placebo (P<0.001). Changes in HDL-C were correlated to changes in adiponectin (r=0.34; P=0.01) but not to changes in insulin resistance. PIO did not affect serum triglycerides or low-density lipoprotein (LDL) cholesterol concentrations but reduced the number of small LDL particles by 18% (P<0.001). PIO reduced median C-reactive protein levels by 31% (P<0.001) and mean resistin levels by 10% (P=0.02) while increasing mean serum levels of adiponectin by 111% (P<0.001) compared with placebo. PIO did not affect weight and modestly decreased insulin resistance.In nondiabetic patients with low HDL-C and MetSyn, PIO significantly raised HDL-C and favorably affected lipoprotein particle size, markers of inflammation, and adipokines without changes in triglycerides, LDL-C, or weight. These results suggest that PIO has direct effects on HDL, which may contribute to its antiatherogenic effects.
Chronic inflammation converges in type 2 diabetes and atherosclerosis. Modulation of adipokine signaling by innate immunity in humans is of considerable interest given the role of adipokines in insulin resistance and atherosclerosis.The aim of the study was to examine effects of low-grade endotoxemia, a model of human inflammation, on adipokines in vivo.An open-label, placebo-controlled, fixed-sequence clinical study was conducted at a General Clinical Research Center.There were 20 healthy male (50%) and female volunteers aged 18-40 yr.Serial blood sampling and adipose biopsies were performed for 24 h before and after iv bolus endotoxin [lipopolysaccharide (LPS), 3 ng/kg].We measured plasma leptin, adiponectin, resistin, soluble leptin receptor, cytokines, insulin, and glucose; distribution of adiponectin among multimeric complexes; whole blood, monocyte and adipose mRNA for adipokines and their receptors.LPS induced fever, blood, and adipose TNF and IL-6 and increased homeostasis model assessment of insulin resistance. These were associated with increases in plasma leptin (from 4.1 +/- 1.1 to 6.1 +/- 1.9 ng/ml in men; 21.1 +/- 4.4 to 27.4 +/- 4.7 ng/ml in women; P < 0.005), doubling of the leptin:soluble leptin receptor ratio, and marked induction of whole blood resistin mRNA (13.7 +/- 7.3-fold; P < 0.001) and plasma resistin (8.5 +/- 2.75 to 43.2 +/- 15.3 ng/ml; P < 0.001). Although total adiponectin levels and low and high molecular weight adiponectin complexes were unaltered by LPS treatment, whole blood mRNA for adiponectin receptors 1 (49%; P < 0.005) and 2 (65%; P < 0.001) was suppressed.Modulation of adipokine signaling may contribute to the insulin resistant, atherogenic state associated with human inflammatory syndromes. Targeting of individual adipokines or their upstream regulation may prove effective in preventing acute and chronic inflammation-related metabolic complications.
Background— Plasma levels of high-density lipoprotein cholesterol (HDL-C) are known to be heritable, but only a fraction of the heritability is explained. We used a high-density genotyping array containing single-nucleotide polymorphisms (SNPs) from HDL-C candidate genes selected on known biology of HDL-C metabolism, mouse genetic studies, and human genetic association studies. SNP selection was based on tagging SNPs and included low-frequency nonsynonymous SNPs. Methods and Results— Association analysis in a cohort containing extremes of HDL-C (case-control, n=1733) provided a discovery phase, with replication in 3 additional populations for a total meta-analysis in 7857 individuals. We replicated the majority of loci identified through genome-wide association studies and present on the array (including ABCA1, APOA1/C3/A4/A5, APOB, APOE/C1/C2, CETP, CTCF-PRMT8, FADS1/2/3, GALNT2, LCAT, LILRA3, LIPC, LIPG, LPL, LRP4, SCARB1, TRIB1, ZNF664 ) and provide evidence that suggests an association in several previously unreported candidate gene loci (including ABCG1, GPR109A/B/81, NFKB1, PON1/2/3/4 ). There was evidence for multiple, independent association signals in 5 loci, including association with low-frequency nonsynonymous variants. Conclusions— Genetic loci associated with HDL-C are likely to harbor multiple, independent causative variants, frequently with opposite effects on the HDL-C phenotype. Cohorts comprising subjects at the extremes of the HDL-C distribution may be efficiently used in a case-control discovery of quantitative traits.
