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Marja-Riitta Taskinen

Publications and source records attributed to Marja-Riitta Taskinen.

At least 37 records · Page 2Linked to original sources

Lifestyle modification improves risk factors in type 2 diabetes relatives.

AIMS: To investigate the short-term (16 weeks) effect of lifestyle intervention on insulin sensitivity, anthropometric and metabolic variables in non-diabetic first-degree relatives of type 2 diabetic patients (FDR). METHODS: Seventy-seven (49 male, 28 female) FDR were allocated to one of three groups, diet (D-group; n = 25), diet and exercise (DE-group; n = 30) or control group (C-group; n = 22). Lifestyle counselling was based on current nutrition recommendations, including increased intake of fatty fish and low glycaemic index foods. Group counselling was given on two occasions with follow-up through telephone interviews every 10 days. Assessments included insulin sensitivity index (Si), anthropometry, lipid parameters, circulating leptin and adiponectin levels. RESULTS: The D-group reduced total cholesterol (-0.31 mmol/l, P = 0.024), LDL cholesterol (-0.22 mmol/l, P = 0.021) and apolipoprotein B (-9.5 mg/dl, P = 0.009) levels, whereas the DE-group decreased body weight (-2.1%, P = 0.030) and waist circumference (-3.0 cm, P < 0.001) versus controls. A 13% reduction in fasting insulin was observed in the DE-group, but no significant improvement in Si in D-group or DE-group was observed. A subgroup, adherent to diet and who increased exercise, significantly improved Si and lipid profile. CONCLUSIONS: The improved metabolic risk profile in FDR suggests that lifestyle changes can be effective in individuals at high risk to develop type 2 diabetes and cardiovascular disease.

Adult↗

Fenofibrate reduces progression to microalbuminuria over 3 years in a placebo-controlled study in type 2 diabetes: results from the Diabetes Atherosclerosis Intervention Study (DAIS).

BACKGROUND: Microalbuminuria is an early marker of diabetic nephropathy and an independent risk factor for cardiovascular disease. In the Diabetes Atherosclerosis Intervention Study (DAIS), treatment of people with type 2 diabetes with micronized fenofibrate for an average of 38 months reduced the progression of angiographically evaluated coronary artery disease and improved lipoprotein level abnormalities compared with placebo. The aim of this analysis is to study the influence of the treatment on changes in urinary albumin excretion. METHODS: Microalbuminuria was measured on 2 to 3 occasions by using timed overnight samples at baseline and yearly thereafter in 314 DAIS participants (77 women, 237 men; average age, 56 years); all except 3 participants had either a normal albumin excretion rate (<20 microg/min; n = 214) or microalbuminuria (albumin, 20 to 200 microg/min; n = 97) before randomization. Tabulated shifts (between normal, microalbuminuria, and macroalbuminuria) from baseline to last observed values were compared between treatment groups by means of chi-square or Fisher's exact test. RESULTS: Fenofibrate significantly reduced the worsening of albumin excretion (fenofibrate, 8% versus placebo, 18%; P < 0.05). This effect was caused mostly by reduced progression from normal albumin excretion to microalbuminuria: 3 of 101 participants in the fenofibrate group versus 20 of 113 participants in the placebo group (P < 0.001). Overall, changes in albumin excretion were independent of age or changes in lipid or creatinine levels, weight, or blood pressure. CONCLUSION: Improvement in lipid profiles with fenofibrate in patients with type 2 diabetes was associated with reduced progression from normal albumin excretion to microalbuminuria.

Albuminuria↗

Insulin-mediated down-regulation of apolipoprotein A5 gene expression through the phosphatidylinositol 3-kinase pathway: role of upstream stimulatory factor.

The apolipoprotein A5 gene (APOA5) has been repeatedly implicated in lowering plasma triglyceride levels. Since several studies have demonstrated that hyperinsulinemia is associated with hypertriglyceridemia, we sought to determine whether APOA5 is regulated by insulin. Here, we show that cell lines and mice treated with insulin down-regulate APOA5 expression in a dose-dependent manner. Furthermore, we found that insulin decreases human APOA5 promoter activity, and subsequent deletion and mutation analyses uncovered a functional E box in the promoter. Electrophoretic mobility shift and chromatin immunoprecipitation assays demonstrated that this APOA5 E box binds upstream stimulatory factors (USFs). Moreover, in transfection studies, USF1 stimulates APOA5 promoter activity, and the treatment with insulin reduced the binding of USF1/USF2 to the APOA5 promoter. The inhibition of the phosphatidylinositol 3-kinase (PI3K) pathway abolished insulin's effect on APOA5 gene expression, while the inhibition of the P70 S6 kinase pathway with rapamycin reversed its effect and increased APOA5 gene expression. Using an oligonucleotide precipitation assay for USF from nuclear extracts, we demonstrate that phosphorylated USF1 fails to bind to the APOA5 promoter. Taken together, these data indicate that insulin-mediated APOA5 gene transrepression could involve a phosphorylation of USFs through the PI3K and P70 S6 kinase pathways that modulate their binding to the APOA5 E box and results in APOA5 down-regulation. The effect of exogenous hyperinsulinemia in men showed a decrease in the plasma ApoAV level. These results suggest a potential contribution of the APOA5 gene in hypertriglyceridemia associated with hyperinsulinemia.

Adult↗

Predictors of and longitudinal changes in insulin sensitivity and secretion preceding onset of type 2 diabetes.

Identification of individuals at high risk of developing type 2 diabetes is a prerequisite for prevention of the disease. We therefore studied risk factors predicting type 2 diabetes in the Botnia Study in Western Finland. A total of 2,115 nondiabetic individuals were prospectively followed with repeated oral glucose tolerance tests. After a median follow-up of 6 years, 127 (6%) subjects developed diabetes. A family history of diabetes (hazard ratio [HR] 2.2, P = 0.008), BMI (HR for comparison of values below or above the median 2.1, P < 0.001), waist-to-height index (2.3, P < 0.001), insulin resistance (2.1, P = 0.0004), and beta-cell function adjusted for insulin resistance (2.7, P < 0.0001) predicted diabetes. Marked deterioration in beta-cell function with modest changes in insulin sensitivity was observed during the transition to diabetes. The combination of FPG > or =5.6 mmol/l, BMI > or =30 kg/m(2), and family history of diabetes was a strong predictor of diabetes (3.7, P < 0.0001). Of note, using FPG > or =6.1 mmol/l or 2-h glucose > or =7.8 mmol/l did not significantly improve prediction of type 2 diabetes. In conclusion, a marked deterioration in beta-cell function precedes the onset of type 2 diabetes. These individuals can be identified early by knowledge of FPG, BMI, and family history of diabetes.

Adult↗

Metabolic syndrome in type 1 diabetes: association with diabetic nephropathy and glycemic control (the FinnDiane study).

OBJECTIVE: The aim of this study was to estimate the prevalence of the metabolic syndrome in Finnish type 1 diabetic patients and to assess whether it is associated with diabetic nephropathy or poor glycemic control. RESEARCH DESIGN AND METHODS: In all, 2,415 type 1 diabetic patients (51% men, mean age 37 years, duration of diabetes 22 years) participating in the nationwide, multicenter Finnish Diabetic Nephropathy (FinnDiane) study were included. Metabolic syndrome was defined according to the National Cholesterol Education Program diagnostic criteria. Patients were classified as having normal albumin excretion rate (AER) (n = 1,261), microalbuminuria (n = 326), macroalbuminuria (n = 383), or end-stage renal disease (ESRD) (n = 164). Glycemic control was classified as good (HbA1c <7.5%), intermediate (7.5-9.0%), or poor (>9.0%). Creatinine clearance was estimated with the Cockcroft-Gault formula. RESULTS: The overall prevalence of metabolic syndrome was 38% in men and 40% in women. The prevalence was 28% in those with normal AER, 44% in microalbuminuric patients, 62% in macroalbuminuric patients, and 68% in patients with ESRD (P < 0.001). Patients with metabolic syndrome had a 3.75-fold odds ratio for diabetic nephropathy (95% CI 2.89-4.85), and all of the separate components of the syndrome were independently associated with diabetic nephropathy. The prevalence of metabolic syndrome was 31% in patients with good glycemic control, 36% in patients with intermediate glycemic control, and 51% in patients with poor glycemic control (P < 0.001). Similarly, metabolic syndrome increased with worsening creatinine clearance. CONCLUSIONS: The metabolic syndrome is a frequent finding in type 1 diabetes and increases with advanced diabetic nephropathy and worse glycemic control.

Adult↗

A new combined multicompartmental model for apolipoprotein B-100 and triglyceride metabolism in VLDL subfractions.

The use of stable isotopes in conjunction with compartmental modeling analysis has greatly facilitated studies of the metabolism of the apolipoprotein B (apoB)-containing lipoproteins in humans. The aim of this study was to develop a multicompartment model that allows us to simultaneously determine the kinetics of apoB and triglyceride (TG) in VLDL(1) and VLDL(2) after a bolus injection of [(2)H(3)]leucine and [(2)H(5)]glycerol and to follow the catabolism and transfer of the lipoprotein particles. Here, we describe the model and present the results of its application in a fasting steady-state situation in 17 subjects with lipid values representative of a Western population. Analysis of the correlations showed that plasma TG was determined by the VLDL(1) and VLDL(2) apoB and TG fractional catabolic rate. Furthermore, the model showed a linear correlation between VLDL(1) TG and apoB production. A novel observation was that VLDL TG entered the circulation within 21 min after its synthesis, whereas VLDL apoB entered the circulation after 33 min. These observations are consistent with a sequential assembly model of VLDL and suggest that the TG is added to a primordial apoB-containing particle in the liver.

Apolipoprotein B-100↗

Active and low-active forms of serum phospholipid transfer protein in a normal Finnish population sample.

Human serum phospholipid transfer protein (PLTP) exists as a catalytically active (HA-PLTP) and a low-active (LA-PLTP) form. In this study, the association of PLTP activity and the concentrations of both forms with lipid and carbohydrate parameters were investigated. In a random Finnish population sample, serum PLTP concentration (n=250) was 6.56 +/- 1.45 mg/l, the mean lipoprotein-independent (PLTPexo) phospholipid transfer activity was 6.59 +/- 1.66 micromol/ml/h, and the mean lipoprotein-dependent (PLTPendo) activity was 1.37 +/- 0.29 micromol/ml/h. Of the serum PLTP concentration, approximately 46% was in a catalytically active form. HA-PLTP concentration correlated positively with serum PLTPexo activity (r=0.380, P <0.001), HDL cholesterol (r=0.291, P <0.001), and apolipoprotein A-I (r=0.187, P <0.01). Of the potential regulatory factors for PLTP, apolipoprotein E showed a weak positive correlation with serum PLTPexo (r=0.154, P <0.05) and PLTPendo (r=0.192, P <0.01) activity but not with PLTP concentration. Weak associations were also observed between PLTP parameters and determinants of glucose homeostasis (glucose, insulin, and homeostasis model assessment for insulin resistance). The present data on PLTP activity and concentration reveal novel connections of the two PLTP forms to lipid and carbohydrate metabolism.

Cholesterol, HDL↗

Locus for quantitative HDL-cholesterol on chromosome 10q in Finnish families with dyslipidemia.

Decreased HDL-cholesterol (HDL-C) and familial combined hyperlipidemia (FCHL) are the two most common familial dyslipidemias predisposing to premature coronary heart disease (CHD). These dyslipidemias share many phenotypic features, suggesting a partially overlapping molecular pathogenesis. This was supported by our previous pooled data analysis of the genome scans for low HDL-C and FCHL, which identified three shared chromosomal regions for a qualitative HDL-C trait on 8q23.1, 16q23.3, and 20q13.32. This study further investigates these regions as well as two other loci we identified earlier for premature CHD on 2q31 and Xq24 and a locus for high serum triglycerides (TGs) on 10q11. We analyzed 67 microsatellite markers in an extended study sample of 1,109 individuals from 92 low HDL-C or FCHL families using both qualitative and quantitative lipid phenotypes. These analyses provided evidence for linkage (a logarithm of odds score of 3.2) on 10q11 using a quantitative HDL-C trait. Importantly, this region, previously linked to TGs, body mass index, and obesity, provided evidence for association for quantitative TGs (P = 0.0006) and for a combined trait of HDL-C and TGs (P = 0.008) with marker D10S546. Suggestive evidence for linkage also emerged for HDL-C on 2q31 and for TGs on 20q13.32. Finnish families ascertained for dyslipidemias thus suggest that 10q11, 2q31, and 20q13.32 harbor loci for HDL-C and TGs.

Adult↗

Circulating oxidized low-density lipoprotein and its association with carotid intima-media thickness in asymptomatic members of familial combined hyperlipidemia families.

OBJECTIVE: Oxidized low-density lipoprotein (Ox-LDL)is implicated in the pathogenesis of atherosclerosis. Circulating oxidation-specific epitopes on plasma Ox-LDL has been linked with coronary artery disease, but its determinants and its association with early development of atherosclerosis in familial combined hyperlipidemia (FCHL) has not been very well studied. This study aimed to investigate the determinants of the circulating Ox-LDL and the association between Ox-LDL and carotid intima-media thickness (IMT) in asymptomatic members of FCHL families. METHODS AND RESULTS: Ox-LDL, susceptibility of LDL to oxidation in vitro, plasma 8-isoprostane and antioxidants, lipids and lipoproteins, LDL particle size, and carotid IMT were measured in 150 asymptomatic FCHL family members. Affected FCHL family members had reduced LDL particle size and lag time for LDL oxidation, increased plasma levels of Ox-LDL, increased plasma urate and alpha-tocopherol, and a trend for the increase of 8-isoprostane as compared with nonaffected FCHL. Ox-LDL was independently associated with serum LDL cholesterol, apoB, and 8-isoprostane in multivariate analysis but only univariately correlated with LDL particle size and lag time for LDL oxidation. In addition, Ox-LDL was significantly associated with carotid mean IMT independently of other clinical and biochemical variables in a multivariate model. CONCLUSIONS: Serum LDL cholesterol, apoB levels, and 8-isoprostane were the most important determinants of Ox-LDL. Ox-LDL is independently associated with carotid IMT in asymptomatic FCHL family members and can be used as a marker of early atherosclerosis in FCHL.

Adult↗

Familial combined hyperlipidemia is associated with upstream transcription factor 1 (USF1).

Familial combined hyperlipidemia (FCHL), characterized by elevated levels of serum total cholesterol, triglycerides or both, is observed in about 20% of individuals with premature coronary heart disease. We previously identified a locus linked to FCHL on 1q21-q23 in Finnish families with the disease. This region has also been linked to FCHL in families from other populations as well as to type 2 diabetes mellitus. These clinical entities have several overlapping phenotypic features, raising the possibility that the same gene may underlie the obtained linkage results. Here, we show that the human gene encoding thioredoxin interacting protein (TXNIP) on 1q, which underlies combined hyperlipidemia in mice, is not associated with FCHL. We show that FCHL is linked and associated with the gene encoding upstream transcription factor 1 (USF1) in 60 extended families with FCHL, including 721 genotyped individuals (P = 0.00002), especially in males with high triglycerides (P = 0.0000009). Expression profiles in fat biopsy samples from individuals with FCHL seemed to differ depending on their carrier status for the associated USF1 haplotype. USF1 encodes a transcription factor known to regulate several genes of glucose and lipid metabolism.

Animals↗

APOA5 gene variants, lipoprotein particle distribution, and progression of coronary heart disease: results from the LOCAT study.

Animal and human studies support a role for apolipoprotein A-V (apoA-V) in triglyceride (TG) metabolism. We examined the relationship of APOA5 -1131T>C and S19W with lipid subfractions and progression of atherosclerosis in the Lopid Coronary Angiography Trial. Compared with -1131TT men (n = 242), carriers of the -1131C allele (n = 54) had significantly higher total TG (P = 0.03), reflected in significantly increased VLDL mass [higher VLDL-TG, VLDL-cholesterol, VLDL-protein, and surface lipids (all P < 0.05)]. Because apoB levels were unaffected by genotype, this suggests an increase in VLDL size and not number. Compared with 19SS men (n = 268), 19W carriers (n = 44) had higher intermediate density lipoprotein (IDL)-TG, IDL-cholesterol (P = 0.04), and IDL-surface components [free cholesterol (P = 0.005) and phospholipids (P = 0.017)] but not protein content, suggesting an increase in IDL lipid enrichment resulting in an increase in IDL size. 19W carriers also showed a trend toward increased progression of atherogenesis, as measured by change in average diameter of segments (-0.46 +/- 0.011 mm compared with -0.016 +/- 0.006 mm) in 19SS men (P = 0.08). There was no effect of genotype on the response of these parameters to gemfibrozil treatment. These results shed new light on the role of APOA5 variants in TG metabolism and coronary heart disease risk.

Aged↗

Serum homocysteine concentrations, gemfibrozil treatment, and progression of coronary atherosclerosis.

The present study aimed to assess the effect of gemfibrozil on serum total homocysteine (tHcy) concentration and to evaluate the influence of tHcy on the angiographically determined progression of coronary atherosclerosis in a randomised, placebo-controlled trial of 395 post-coronary bypass men with low HDL cholesterol levels. The baseline levels of tHcy and those after 16 months of randomised therapy were measured by high-pressure liquid chromatography. Patients were genotyped for the thermolabile variant of N5,N10-methylenetetrahydrofolate reductase (MTHFR) (677C > T substitution). Gemfibrozil therapy was associated with a median 18% increase in tHcy levels (P < 0.01). In the gemfibrozil group increases in tHcy and HDL cholesterol were related (r = 0.217, P = 0.004), but changes in tHcy and triglycerides were not. Levels of tHCy were not associated with baseline extent or progression of coronary-artery disease. Subjects homozygous for the rare MTHFR T allele had 34% higher median tHcy concentrations than CC homozygotes or CT heterozygotes, but responses to gemfibrozil did not differ significantly among genotypes. The MTHFR genotype was not associated with extent or progression of coronary atherosclerosis. We conclude that gemfibrozil causes a significant elevation in tHcy levels, but the clinical relevance of this is unknown at present.

Cholesterol, HDL↗

R643G polymorphism in PECAM-1 influences transendothelial migration of monocytes and is associated with progression of CHD and CHD events.

The 643R allele of R643G polymorphism (also known as R670G in the premature protein) in PECAM-1 has been associated with risk of myocardial infarction (MI), while the 643G allele has been associated with risk of coronary artery stenosis (CAS). The aim of this study was to investigate this apparently conflicting association. The association of R643G with risk of MI was determined in the second Northwick Park Heart study (2037 men with 138 CHD events; mean age: 56 years). Smokers homozygous for the 643R allele showed increased risk of MI with a hazard ratio of 2.47 (95% CI: 1.23-4.97; P=0.01) compared to smokers homozygous for the 643G allele. Progression of disease was determined in the Lopid Coronary Angiography Trial (279 men; mean age: 58.9 years). The 643G homozygotes showed greater focal (-0.08 +/- 0.02 mm) and diffuse (-0.01 +/- 0.01 mm) progression of CAS compared to 643R homozygotes (-0.02 +/- 0.02 mm and 0.001 +/- 0.01 mm, respectively; P=0.04). While there was no genotype effect on platelet aggregation, PECAM-1 tyrosine phosphorylation in HUVECs of GG genotype was 2.4-fold greater (P <0.01) than cells of RR genotype, and the level of transendothelial migration of monocytes of GG genotype was greater than that of monocytes of RR genotype following stimulation with either IL-1beta (12% higher, P <0.01) or TNF-alpha (10% higher, P=0.05). These data confirm the association of the R643G polymorphism with MI and CAS and suggest that greater influx of monocytes in individuals homozygous for the 643G may explain the association with CAS.

Cell Movement↗

Lipoprotein metabolism in subjects with hepatic lipase deficiency.

A heritable deficiency of hepatic lipase (HL) provides insights into the physiologic function of HL in vivo. The metabolism of apolipoprotein B (apoB)-100 in very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and low-density lipoprotein (LDL) and of apoA-I and apoA-II in high-density lipoprotein (HDL) particles lipoprotein (Lp)(AI) and Lp(AI:AII) was assessed in 2 heterozygous males for compound mutations L334F/T383M or L334F/R186H, with 18% and 22% of HL activity, respectively, compared with 6 control males. Subjects were provided with a standard Western diet for a minimum of 3 weeks. At the end of the diet period, apo kinetics was assessed using a primed-constant infusion of [5,5,5-(2)H(3)] leucine. Mean plasma triglyceride (TG) and HDL cholesterol levels were 55% and 12% higher and LDL cholesterol levels 19% lower in the HL patients than control subjects. A higher proportion of apoB-100 was in the VLDL than IDL and LDL fractions of HL patients than control subjects due to a lower VLDL apoB-100 fractional catabolic rate (FCR) (4.63 v 9.38 pools/d, respectively) and higher hepatic production rate (PR) (33.24 v 10.87 mg/kg/d). Delayed FCR of IDL (2.78 and 6.31 pools/d) and LDL (0.128 and 0.205 pools/d) and lower PR of IDL (3.67 and 6.68 mg/kd/d) and LDL 4.57 and 13.07 mg/kg/d) was observed in HL patients relative to control subjects, respectively. ApoA-I FCR (0.09 and 0.13 pools/d) and PR (4.01 and 6.50 mg/kg/d) were slower in Lp(AI:AII) particles of HL patients relative to control subjects, respectively, accounting for the somewhat higher HDL cholesterol levels. HL deficiency may result in a lipoprotein pattern associated with low heart disease risk.

Adult↗

Effects of a Mediterranean-inspired diet on blood lipids, vascular function and oxidative stress in healthy subjects.

Mediterranean-inspired diets have been shown to decrease cholesterol levels in patients with hypercholesterolaemia, who frequently exhibit endothelial dysfunction. The aims of the present study are to improve endothelial function by dietary intervention in healthy subjects with lipid levels representative of a Western population. Twenty-two healthy subjects (mean total cholesterol, 5.6 mmol/l) were given a Mediterranean-inspired diet rich in omega-3 fatty acids and sterol esters, but low in saturated fat, or an ordinary Swedish diet, for 4 weeks in a randomized cross-over study. The composition of the diets were: in the Swedish diet, 2090 kcal (where 1 kcal=4.184 kJ; 48% of energy from carbohydrate, 15% from protein and 36% from fat) and 19 g of fibre; in the Mediterranean-inspired diet, 1869 kcal (48% of energy from carbohydrate, 16% from protein, 34% from fat) and 40 g of fibre. After each dietary period, fasting blood lipids, insulin and glucose levels, as well as apo B (apolipoprotein B) and LDL (low-density lipoprotein) particle size, were analysed. Endothelial-dependent and -independent vasodilation was measured invasively by venous occlusion plethysmography, and arterial distensibility was assessed by echocardiography tracking. Fibrinolytic capacity across the forearm, as well as oxidative stress measured through urinary F(2)-isoprostane, were evaluated. Total, LDL- and apo B-cholesterol and triacylglycerol (triglyceride) concentrations were decreased by 17%, 22%, 16% and 17% respectively, after the Mediterranean-inspired diet compared with the Swedish diet ( P <0.05 for all). However, no differences in plasma concentrations of insulin and glucose and LDL particle size, endothelial function, arterial distensibility, fibrinolytic capacity or oxidative stress were detected. Treatment for 4 weeks with a Mediterranean-inspired diet decreased blood lipids in healthy individuals with a low-risk profile for cardiovascular disease. This beneficial effect was not mirrored in vascular function or oxidative stress evaluation.

Adult↗

Determinants of low HDL levels in familial combined hyperlipidemia.

In familial combined hyperlipidemia (FCHL), affected family members frequently have reduced levels of HDL cholesterol, in addition to elevated levels of total cholesterol and/or triglycerides (TGs). In the present study, we focused on those determinants that are important regulators of HDL cholesterol levels in FCHL, and measured postheparin plasma activities of hepatic lipase (HL), lipoprotein lipase, cholesterol ester transfer protein, and phospholipid transfer protein (PLTP) in 228 subjects from 49 FCHL families. In affected family members (n = 88), the levels of HDL cholesterol, HDL2 cholesterol, HDL3 cholesterol, and apolipoprotein A-I were lower than in unaffected family members (n = 88) or spouses (n = 52). The main change was the reduction of HDL2 cholesterol by 25.4% in affected family members (P < 0.001 vs. unaffected family members; P = 0.003 vs. spouses). Affected family members had higher HL activity than unaffected family members (P = 0.001) or spouses (P = 0.013). PLTP activity was higher in affected than unaffected family members (P = 0.025). In univariate correlation analysis, a strong negative correlation was observed between HL activity and HDL2 cholesterol (r = -0.339, P < 0.001). Multivariate regression analysis demonstrated that gender, HL activity, TG, and body mass index have independent contributions to HDL2 cholesterol levels. We suggest that in FCHL, TG enrichment of HDL particles and enhanced HL activity lead to the reduction of HDL cholesterol and HDL2 cholesterol.

Adult↗

Relationships between low-density lipoprotein particle size, plasma lipoproteins, and progression of coronary artery disease: the Diabetes Atherosclerosis Intervention Study (DAIS).

BACKGROUND: The Diabetes Atherosclerosis Intervention Study showed that treatment with fenofibrate decreases progression of coronary atherosclerosis in subjects with type 2 diabetes. We determined whether on-treatment plasma lipid concentrations and LDL particle size contribute to the favorable effect of fenofibrate on the progression of coronary artery disease (CAD). METHODS AND RESULTS: A total of 418 subjects with type 2 diabetes were randomly assigned to 200 mg micronized fenofibrate daily or placebo. The mean follow-up time was 39.6 months. LDL peak particle diameter (LDL size) was determined by polyacrylamide gradient gel electrophoresis from 405 subjects at baseline and at the end of the study. Progression of CAD was measured with quantitative coronary angiography. LDL size increased significantly more in the fenofibrate group than in the placebo group (0.98+/-1.04 versus 0.32+/-0.92 nm, P<0.001). In the combined group, small LDL size was significantly associated with progression of CAD measured as the increase of percentage diameter stenosis (r=-0.16, P=0.002) and decreases in minimum (r=-0.11, P=0.030) and mean (r=-0.10, P=0.045) lumen diameter. High on-treatment LDL cholesterol, apolipoprotein B, and triglyceride concentrations were also associated with the progression of CAD. In regression analyses, small LDL size added to the effect of LDL cholesterol and apolipoprotein B on the progression of CAD. Similar associations were observed in the fenofibrate group, whereas in the placebo group, lipoprotein variables were not significantly correlated with the progression of CAD. CONCLUSIONS: Changes in LDL size and plasma lipid levels account for part of the antiatherogenic effect of fenofibrate in type 2 diabetes.

Adult↗

Combined analysis of genome scans of dutch and finnish families reveals a susceptibility locus for high-density lipoprotein cholesterol on chromosome 16q.

Several genomewide screens have been performed to identify novel loci predisposing to unfavorable serum lipid levels and coronary heart disease (CHD). We hypothesized that the accumulating data of these screens in different study populations could be combined to verify which of the identified loci truly harbor susceptibility genes. The power of this strategy has recently been demonstrated with other complex diseases, such as inflammatory bowel disease and asthma. We assessed the largely unknown genetic background of CHD by investigating the most common dyslipidemia predisposing to CHD, familial combined hyperlipidemia (FCHL), affecting 1%-2% of Western populations and 10%-20% of families with premature CHD. To be able to perform a combined data analysis, we unified the diagnostic criteria for FCHL and its component traits and combined the data from two genomewide scans performed in two populations, the Finns and the Dutch. As a result of our pooled data analysis, we identified three chromosomal regions, on chromosomes 2p25.1, 9p23, and 16q24.1, exceeding the statistical significance level of a LOD score >2.0. The 2p25.1 region was detected for the FCHL trait, and the 9p23 and 16q24.1 regions were detected for the low high-density lipoprotein cholesterol (HDL-C) trait. In addition, the previously recognized 1q21 region also obtained additional support in the other study sample, when the triglyceride trait was used. Analysis of the 16q24.1 region resulted in a statistically significant LOD score of 3.6 when the data from Finnish families with low HDL-C were included in the analysis. To search for the underlying gene in the 16q24.1 region, we investigated a novel functional and positional candidate gene, helix/forkhead transcription factor (FOXC2), by sequencing and by genotyping of two single-nucleotide polymorphisms in the families.

Cholesterol, HDL↗