Jey Sook Chae

Effect of oral administration of testosterone on brachial arterial vasoreactivity in men with coronary artery disease

H igh androgen levels in men have been regarded as a risk factor for coronary artery disease (CAD). However, it has recently been demonstrated that supplements of androgens inhibit atheroma formation in castrated male animals, suggesting that testosterone may be antiatherosclerotic. In men with angina pectoris, a significant inverse correlation was found between plasma testosterone levels and the extent of CAD, demonstrating that low testosterone levels could be a risk factor for CAD. Other reports suggest that testosterone replacement therapy in men with CAD has a beneficial effect on angina pectoris and exercise-induced ST-segment depression. Another study showed that testosterone enhanced endotheliumindependent coronary artery dilation and flow-mediated brachial arterial vasoreactivity in men with CAD. In this study, we assessed the effects of oral testosterone administration on brachial arterial vasoreactivity in men with CAD. • • • Thirty-five men (aged 58 8 years) with CAD were randomized to placebo (n 17) or treatment group (n 18). Demographics of the study group are summarized in Table 1. Diagnostic criteria of CAD are a history of unstable and stable angina pectoris with angiographic evidence ( 50% stenosis of lumen diameter). Exclusion criteria were inflammatory disease or malignancy, ejection fraction 45%, clinical evidence of heart failure, and Q-wave myocardial infarction within 3 months before the study. The treatment group completed oral administration of 160 mg of testosterone undecanoate (Andriol, N.V. Organon, Oss, The Netherlands) daily for 4 weeks followed by 80 mg testosterone undecanoate for 8 weeks, in addition to their current medication. Using high-resolution ultrasound, we assessed brachial arterial vasoreactivity to reactive hyperemia (flow-mediated dilation) and sublingual nitroglycerin (nitroglycerin-mediated dilation) at baseline and after 12 weeks of treatment. Patients taking nitrates discontinued therapy 24 hours before the study to avoid nitrate tolerance. A 10-MHz linear phased-array ultrasound transducer (GE Vigmed Ultrasound, Horten, Norway) was used to image the dominant arm brachial artery longitudinally 3 to 5 cm just above the antecubital fossa. All patients rested in the supine position for 10 minutes in a quiet room. After the depth and gain setting were optimized to identify the vessel wall, the brachial artery diameter was measured from the anterior to the posterior interface between the media and the adventitia and determined at end-diastole on B mode. Reactive hyperemia was induced by inflation and then deflation of a pneumatic cuff placed around the upper arm. The blood pressure cuff was inflated to 250 mm Hg for 5 minutes. After release of the cuff, brachial artery diameter was measured within the first 15 seconds of reactive hyperemia. The brachial artery was allowed to return to the baseline level until 10 minutes after cuff release. Then, a further baseline brachial artery diameter was obtained. Nitroglycerin, 0.6 mg, was then given sublingually, and the brachial artery diameter was measured for the ensuing 3 minutes. The percent change in diameter caused by reactive hyperemia was calculated by dividing the difference from baseline end-diastolic diameter by the baseline value. The percent change in diameter caused by nitroglycerin administration was also calculated in the same way. Blood pressure and heart rate were measured before the examination. All data were calculated as an average of 4 consecutive cardiac cycles. Early morning blood sampling for fasting lipid profiles was performed and plasma-free testosterone levels were obtained immediately before ultrasound imaging and 12 weeks later. A standard radioimmunoassay method was used for analysis (DSL-4900 kit, Diagnostic System Laboratory Inc., Houston, Texas). All descriptive data are presented as mean SD and analyzed using SPSS for Windows 9.0 (SPSS Inc., Chicago, Illinois) From the Cardiology Division, Yonsei Cardiovascular Center and Cardiovascular Research Institute, College of Medicine, Seoul; and Department of Food and Nutrition, College of Ecology, Yonsei University, Seoul, South Korea. Dr. Jang’s address is: Cardiology Division, Yonsei Cardiovascular Center, Yonsei University College of Medicine, 134, Shinchon-Dong, Seodaemun-Gu, Seoul 120-752, South Korea. E-mail: jangys1212@yumc.yonsei.ac.kr. Manuscript received August 10, 2001; revised manuscript received and accepted December 10, 2001. TABLE 1 Clinical Characteristics of Study Group

The apolipoprotein A5 -1131T > C promoter polymorphism in Koreans: association with plasma APOA5 and serum triglyceride concentrations, LDL particle size and coronary artery disease.

BACKGROUND The association between -1131T>C single nucleotide polymorphism (SNP) of the apolipoprotein A5 gene (APOA5) and hypertriglyceridemia raised the possibility that this SNP could be related to coronary artery disease (CAD) risk. Therefore, we investigated the association of this APOA5 -1131T>C SNP with circulating concentrations of APOA5, triglyceride and CAD in Koreans. METHODS CAD patients (n=741) and age-, sex-matched healthy controls (n=741) were genotyped for the APOA5 -1131T>C SNP. The main outcome measures were the odds ratio (OR) on CAD risk and lipid variables, APOA5 concentration and LDL particle size. RESULTS The presence of the minor allele at the -1131T>C SNP was associated with an increased risk of CAD [OR 1.34 (95% CI, 1.09-1.65), P=0.007] after adjusting for BMI, alcohol consumption, systolic blood pressure and diastolic blood pressure. There was an association between the APOA5 concentration and the -1131T>C genotype in controls (T/T: 245+/-7 ng/ml, T/C: 220+/-6, C/C: 195+/-12; P=0.001) and CAD patients (T/T: 218+/-8 ng/ml, T/C: 185+/-7, C/C: 169+/-12; P<0.001). Subjects with T/C or C/C in control and CAD patient groups showed higher triglyceride than those with T/T genotype. Also, the -1131T>C polymorphism was associated with LDL particle size (P=0.003), with the T/C or C/C controls having smaller size than the T/T controls. CONCLUSIONS The APOA5 -1131C allele is associated with reduced APOA5 concentration and with increased CAD risk. This is consistent with the observed association between the -1131C SNP, increased triglycerides as well as small LDL particle size.

Atherogenecity of LDL and Unfavorable Adipokine Profile in Metabolically Obese, Normal-weight Woman

Objective: The relationship of visceral adiposity with adipocytokines and low‐density lipoprotein (LDL) particle distribution and oxidation in Asian metabolically obese, normal‐weight (MONW) individuals has not been evaluated. We aimed to investigate the association between visceral adiposity and adipocytokines and cardiovascular disease (CVD) risk factors in MONW Korean women with normal glucose tolerance.

Genetic variation at the perilipin locus is associated with changes in serum free fatty acids and abdominal fat following mild weight loss.

Objective:Perilipin (PLIN) is a class of protein-coating lipid droplets in adipocytes. We aimed to examine the association between common single-nucleotide polymorphisms (SNPs) at PLIN locus with circulating free fatty acid (FFA) and abdominal fat distribution in response to weight loss.Methods:Non-diabetic/overweight-obese Koreans (n=177) participated in a 12-week calorie restriction (−300kcal/day) program. Seven SNPs (6209T>C, 10076C>G, 10171A>T, 11482G>A, 13042A>G, 13048C>T and 14995A>T), abdominal fat areas (visceral/subcutaneous fat areas at 1st lumbar and 4th lumbar levels), serum lipids, glucose, insulin, FFA, oxidized low-density lipoprotein (LDL) and urinary 8-epi-prostaglandin F2α (PGF2α) were examined.Results:Single-nucleotide polymorphisms 10076C>G/10171A>T showed the strongest positive linkage disequilibrium (LD) (D′=0.923, R 2=0.839, P<0.001) and SNPs11482G>A/14995A>T showed moderate positive LD (D′=0.824, R 2=0.578, P<0.001). Calorie restriction induced 4.6% weight loss with significant abdominal fat reduction. In response to weight loss, subjects with nCA/nCA haplotypes at SNPs 10076C>G/10171A>T showed greater reduction in FFA levels than those with CA/CA haplotype (CA/CA: C/C at SNP 10076 and A/A at SNP 10171, nCA: non-CA haplotype carrier). On the other hand, subjects with nGA/nGA haplotype at SNPs 11482G>A/14995A>T had increased FFA levels with a rapid loss in abdominal fat, whereas GA/GA haplotype carriers had reduction in FFA levels. These results still remained significant after adjusting for age, gender and BMI. Prostaglandin F2α and oxidized LDL were also more reduced in GA/GA haplotype carriers than in nGA haplotype carriers. This effect remained significant after adjusting for baseline level, age, gender and BMI. Paradoxically, nGA haplotype carriers had increased levels of urinary PGF2α after weight reduction.Conclusion:Fasting plasma FFA changes following a modest weight loss in overweight-obese subjects are influenced by the genetic variability at the PLIN locus. Furthermore, circulating FFA changes rather than body fat itself may determine changes in lipid peroxides such as urinary PGF2α and oxidized LDL.

The influence of the adiponectin gene on adiponectin concentrations and parameters of metabolic syndrome in non-diabetic Korean women

BACKGROUND Concentrations of adiponectin, the protein product of the adipocyte C1q and collagen-domain-containing (ADIPOQ) gene are associated with type 2 diabetes and coronary artery disease. We investigate the association of single-nucleotide polymorphisms (SNPs) in the ADIPOQ gene with adiponectin concentrations, and to parameters of metabolic syndrome. METHODS 867 unrelated, non-diabetic Korean women, 20 to 69 y, were genotyped for 8 SNPs in the ADIPOQ gene (-11391G>A, -11377C>G, H241P, Y111H, G90S, R221S, 45T>G, 276G>T). Adiponectin, a homeostasis model assessment of insulin resistance (HOMA-IR), and metabolic parameters were measured. RESULTS Carriers of genotype T/T at position 276 had significantly higher adiponectin concentrations than G/G carriers (P=0.005). Homozygous carriers of the TG haplotype (i.e., individuals who were T/T at 45 and G/G at 276) and heterozygous carriers of the TG haplotype (TG/X) had lower adiponectin concentrations than non-TG carriers (P<0.001). Significant associations between SNP at 276 and serum concentrations of triglyceride (P=0.013), insulin (P=0.013) and HOMA-IR (P=0.012) were found. The 45-276 haplotypes had associations identical to the 276G>T SNP. In subgroup analysis, subjects carrying the TG haplotype had significantly lower adiponectin concentrations than non-TG carriers in both normal weight (P<0.001) and overweight-obese (P=0.009) subgroups. The association of the TG haplotype with increasing insulin concentrations was significant among overweight-obese subjects (P=0.004), but was not significant among normal weight subjects. A similar association was found between the 45-276 haplotype and HOMA-IR. CONCLUSION There is a strong association of the adiponectin SNP276 genotypes and the adiponectin 45-276 haplotypes with circulating adiponectin concentrations in non-diabetic Korean women. In addition, this haplotype is associated with increased insulin concentrations and insulin resistance index only in overweight-obese individuals.

Influence of Adiponectin Gene Polymorphisms on Adiponectin Level and Insulin Resistance Index in Response to Dietary Intervention in Overweight-Obese Patients With Impaired Fasting Glucose or Newly Diagnosed Type 2 Diabetes

OBJECTIVE The aim of this study was to determine the effect of common adiponectin gene polymorphisms on dietary intervention-mediated changes in adiponectin levels and homeostasis model assessment of insulin resistance (HOMA-IR) indexes. RESEARCH DESIGN AND METHODS A total of 363 subjects with impaired fasting glucose (IFG) or newly diagnosed type 2 diabetes followed a dietary intervention (replacement of cooked refined rice with whole grains and an increase in vegetable intake) and regular walking for 12 weeks without any medication. Adiponectin gene single nucleotide polymorphisms (SNPs) (45, 276, and −11377) were examined in these subjects. RESULTS After this dietary intervention, fasting glucose levels decreased in all three SNP 45T>G genotype groups. Subjects with the SNP 45TT genotype showed increased adiponectin levels and decreased HOMA-IR indexes. Haplotype analysis revealed that homozygous carriers of the TG haplotype (45TT and 276GG) and heterozygous carriers of the TG haplotype (TG/X) showed a reduction in the HOMA-IR index after adjustment for baseline levels. Significant differences were observed in changes in HOMA-IR indexes and adiponectin concentrations according to the 45-276 TG haplotype in overweight-obese, but not in normal-weight subjects: the greatest decrease in HOMA-IR indexes and the greatest increase in adiponectin levels were shown in overweight-obese subjects with the TG/TG haplotype. CONCLUSIONS ADIPOQ genetic variants can affect circulating adiponectin levels and insulin resistance indexes in subjects with IFG or newly diagnosed type 2 diabetes in response to dietary intervention.

The association of SNP276G>T at adiponectin gene with circulating adiponectin and insulin resistance in response to mild weight loss

Objective:The purpose of this study was to determine whether common single nucleotide polymorphisms (SNPs) at the adiponectin (ADIPOQ) locus influence changes in circulating adiponectin and the features of insulin resistance in response to a weight loss intervention.Subjects:In total, 294 nondiabetic/overweight–obese Koreans participated in a clinical intervention study lasting 12 weeks involving a caloric reduction of −300kcal/day.Methods:Plasma adiponectin, blood lipids, glucose and insulin concentrations were measured at baseline and after weight loss. Insulin resistance was estimated by homeostasis model assessment insulin resistance (HOMA-IR) derived from fasting glucose and insulin concentrations. We genotyped for three SNPs, 45T>G, 276G>T and −11377C>G.Results:At baseline, HOMA-IR was significantly higher in GG homozygotes than in carriers of the T allele at SNP276G>T of the adiponectin gene (P<0.05). With regard to SNP45T>G and SNP −11377C>G, we did not find any genotype related differences in baseline levels of HOMA-IR and adiponectin. In the 45/276 haplotype test, homozygous for the TG haplotype had significantly lower concentrations of plasma adiponectin (P<0.05). After the 12-week weight loss intervention, the significant decreases in HOMA-IR (P<0.001) and increases in adiponectin (P<0.01) were observed in GG homozygotes at SNP276, which were not shown in carriers of the T allele. Furthermore, there was a significant difference in the decreases in HOMA-IR between the GG homozygotes and carriers of the T allele at SNP276 (P<0.05). Regarding SNP45T>G and SNP −11377C>G, there was no association between SNP45T>G and SNP −11377C>G and decreases in HOMA-IR. In the 45/276 haplotype test, there was a significant difference in changes of adiponectin levels among those with different haplotype combinations (P<0.05).Conclusion:The SNP276G>T of the ADIPOQ gene is associated with different responses of circulating adiponectin and insulin resistance to mild weight loss in overweight-obese subjects.

Mild weight loss reduces inflammatory cytokines, leukocyte count, and oxidative stress in overweight and moderately obese participants treated for 3 years with dietary modification

Obesity-induced oxidative stress and inflammation are involved in the pathogenesis of cardiovascular disease. We investigated whether diet-induced, long-term, mild weight loss improved proinflammatory cytokine levels, leukocyte count, and oxidative stress. Overweight/obese participants (25 ≤ body mass index < 34 kg/m(2), N = 122, 30-59 years) joined a 3-year-long clinical intervention involving daily 100-kcal calorie deficits. Successful weight loss was defined as a reduction in initial body weight equal to 2 kg after the clinical intervention period. Body weight in the successful mild weight loss group (SWL, n = 50) changed 5.4% (-4.16 ± 0.31 kg) compared to 0.05 ± 0.14 kg in the unsuccessful weight loss group (n = 49). After 3 years, SWL participants exhibited significantly reduced insulin, triglycerides, total and low-density lipoprotein cholesterol, free fatty acids, and leukocyte count (P = .030). Furthermore, in the SWL group, serum interleukin (IL)-1β, IL-6, and urinary 8-epi-prostaglandin (PG)F2α were significantly reduced (45%, 30%, and 14%, respectively). In contrast, the unsuccessful weight loss group exhibited significant increases in percentage of body fat, waist circumference, oxidized low-density lipoprotein, and tumor necrosis factor-α, as well as a significant decrease in high-density lipoprotein cholesterol. After adjusting for baseline values, the 2 groups demonstrated significantly different percentage of body fat, waist circumference, leukocyte count (P = .018), insulin, IL-6 (P = .031), IL-1β (P < .001), and tumor necrosis factor-α (P < .001), as well as urinary 8-epi-PGF2α (P = .036). A positive correlation existed between IL-1β and urinary 8-epi-PGF2α (r = 0.435, P < .001) and between changes in IL-6 and urinary 8-epi-PGF2α (r = 0.393, P < .001). Long-term mild weight loss reduces inflammatory cytokine levels, leukocyte counts, and oxidative stress and may reverse the elevated oxidative stress induced by inflammatory mediators in the overweight and obese.

The RANTES -403G > A promoter polymorphism in Korean men : association with serum RANTES concentration and coronary artery disease

In the present study we investigated the association of the RANTES (regulated upon activation, normal T-cell expressed and secreted) -28C>G and -403G>A promoter polymorphisms with the concentration of serum RANTES and CAD (coronary artery disease) in Korean men. We included 553 male CAD patients with (n=176) or without (n=377) Type 2 diabetes, aged 40-65 years with previous myocardial infarction ( approximately 50%) or angiographically confirmed CAD ( approximately 50%), and 416 aged-matched healthy male controls. The main outcome measures were the OR (odds ratio) of CAD risk and the serum RANTES concentration evaluated by sandwich ELISA. Although the RANTES -28C>G genotype had no significant association with CAD risk, the presence of the minor allele of the RANTES -403G>A single nucleotide polymorphism was associated with a lower risk of CAD {OR 0.70 [95% CI (confidence interval) 0.54-0.92], P=0.011} after adjusting for age, BMI (body mass index), cigarette smoking and alcohol consumption. Serum RANTES concentrations were significantly associated with the -403G>A genotype in controls (G/G: 44.7+/-3.3 ng/ml, G/A: 36.5+/-2.0 ng/ml, A/A: 28.7+/-2.5 ng/ml; P<0.001), non-diabetic CAD patients (G/G: 50.9+/-3.0 ng/ml, G/A: 42.2+/-2.6 ng/ml, A/A: 41.3+/-4.4 ng/ml; P<0.05) and diabetic CAD patients (G/G: 58.5+/-3.5 ng/ml, G/A: 49.6+/-4.1 ng/ml, A/A: 42.2+/-4.3 ng/ml; P<0.05); however, such associations were not observed in the subgroup of CAD patients taking lipid-lowering medication. Moreover, serum RANTES was positively correlated with C-reactive protein (r=0.289, P<0.001) and platelet counts (r=0.253, P<0.001). The results of the present study demonstrate that the RANTES -403A allele is associated with lower serum RANTES concentrations and consequently with reduced CAD risk.

Association of apolipoprotein A5 concentration with serum insulin and triglyceride levels and coronary artery disease in Korean men

OBJECTIVE Whereas the relation between apolipoprotein A5 (APOA5) gene polymorphisms and triglycerides (TG) levels is well established, the associations between apoA5 concentrations, TG and coronary artery disease (CAD) remain controversial. Therefore, we investigated these relations in the setting of a case-control study involving Korean males. METHODS ApoA5, TG, insulin, free fatty acid (FFA) and lipoprotein profiles were determined using a cross-sectional design in 777 healthy controls and 367 CAD patients. RESULTS Plasma apoA5 concentration was lower in CAD patients than controls (192.7+/-5.2 vs. 237.2+/-3.7ng/ml, P<0.001). Values in the second and top tertiles of apoA5 were associated with a decreased odds ratio (OR) for CAD when compared with values in the bottom tertile; OR for apoA5 top tertile was 0.33 (95% CI, 0.23-0.47) in the age- and BMI-adjusted model and 0.35 (95% CI, 0.23-0.56) following additional adjustments for smoking, drinking status, blood pressure, TG and HDL-cholesterol. After adjustment for age and BMI, plasma apoA5 concentration was negatively correlated with serum TG (r=-0.188, P<0.001) and insulin (r=-0.185, P<0.001) in normotriglyceridemic controls (TG<150mg/dL, n=509) whereas apoA5 was positively correlated with serum TG in hypertriglyceridemic controls (TG> or =150mg/dL, n=268) (r=0.246, P<0.001) and total CAD patients (r=0.177, P<0.01). Regardless of TG levels and CAD status, apoA5 concentration was positively correlated with HDL-cholesterol and FFA levels. CONCLUSIONS Our data supports an inverse association between plasma apoA5 concentrations and CAD risk, probably due to the observed negative correlations of apoA5 with TGs and insulin, although these correlations were affected by TG levels.