Adiponectin concentrations: a genome-wide association study.

Adiponectin is associated with obesity and insulin resistance. To date, there has been no genome-wide association study (GWAS) of adiponectin levels in Asians. Here we present a GWAS of a cohort of Korean volunteers. A total of 4,001 subjects were genotyped by using a genome-wide marker panel in a two-stage design (979 subjects initially and 3,022 in a second stage). Another 2,304 subjects were used for follow-up replication studies with selected markers. In the discovery phase, the top SNP associated with mean log adiponectin was rs3865188 in CDH13 on chromosome 16 (p = 1.69 × 10(-15) in the initial sample, p = 6.58 × 10(-39) in the second genome-wide sample, and p = 2.12 × 10(-32) in the replication sample). The meta-analysis p value for rs3865188 in all 6,305 individuals was 2.82 × 10(-83). The association of rs3865188 with high-molecular-weight adiponectin (p = 7.36 × 10(-58)) was even stronger in the third sample. A reporter assay that evaluated the effects of a CDH13 promoter SNP in complete linkage disequilibrium with rs3865188 revealed that the major allele increased expression 2.2-fold. This study clearly shows that genetic variants in CDH13 influence adiponectin levels in Korean adults.

Alanine aminotransferase is associated with metabolic syndrome independently of insulin resistance.

BACKGROUND: Few studies have examined the effect of insulin resistance on the association between alanine aminotransferase (ALT) and metabolic syndrome. The association between ALT levels and metabolic syndrome were determined, independently of insulin resistance in Korean populations. METHODS AND RESULTS: The association between ALT and metabolic syndrome were examined in 28,456 subjects who visited 7 Health Promotion Centers at University Hospitals in Korea from 2006 to 2008. HOMA-IR index was used to represent insulin resistance index. ALT levels were found to be positively associated with metabolic syndrome after adjusting for age, alcohol intake, and smoking status. Furthermore, when additional adjustment was made for insulin resistance, this association between ALT and metabolic syndrome, although slightly attenuated, remained strongly significant. Subjects in the highest ALT quartile were found to have a higher risk of having metabolic syndrome than those in the lowest quartile (odds ratio (OR)=4.45, 95% confidence interval (CI)=3.96-4.99 for men and OR=3.51, 95%CI=2.73-4.52 for women). In addition, the association between ALT level and the risk of metabolic syndrome was significantly higher in the relatively low risk group. CONCLUSIONS: ALT levels were found to be significantly associated with metabolic syndrome independently of insulin resistance and with an interaction by age. Further cohort studies are needed to determine the usefulness of ALT levels for predicting the risk of metabolic syndrome.

Heart Rate Recovery and Cancer Risk: Prospective Cohort Study.

This study aims to determine the association between 2-minute heart rate recovery (HRR) and cancer risk. Each participant (5379 women; 8485 men) provided HRR obtained from treadmill tests. The outcome was site-specific cancer. Over 9 years of follow-up, 630 cancer events (258 women) were accrued. Slower HRR was associated with increased thyroid cancer risk in women ( P for trend = .0121) and colorectal cancer risk in men ( P for trend = .0034). The lowest HRR (<13 bpm) had higher hazards of thyroid cancer (hazard ratio [HR] = 2.20; 95% CI = 1.28-3.77) in women and colorectal cancer (HR = 3.08; 95% CI = 1.32-7.15) in men. In women, slower HRR and lower proportions of heart rate recovery (PHRR) were associated with higher hazards of thyroid cancer in women and metabolically related cancers (liver and colorectal) in men. Slower HRR and lower PHRR were independent risk factors for thyroid cancer in women and metabolically related cancers in men.

Preservation of a traditional Korean dietary pattern and emergence of a fruit and dairy dietary pattern among adults in South Korea: secular transitions in dietary patterns of a prospective study from 1998 to 2010.

Transitions in nutrition patterns tend to emerge through industrialization and economic development. We hypothesized that the dietary patterns among South Korean adults who were 20 years or older have changed significantly from 1998 to 2010. Herein, a repeated cross-sectional analysis of data was followed for 140601 adults. We noted changes in consumption, after adjusting for age, sex, body mass index, and exercise, and tested the trends across the study period. Factor and cluster analyses were used to derive dietary patterns. A decrease in traditional Korean food consumption, including cereals, vegetables (252-176 g), and Kimchi (127-82 g), occurred, whereas fruit (172-252 g), egg, and fried food intakes increased (P < .05). Total daily energy intake declined steadily from 1931 in 1998 to 1691 kcal in 2010. Carbohydrate intakes were unchanged over the study period; however, fat-derived energy intake increased slightly from 19.7% to 20.0% (P < .05). Our factor and cluster analyses identified 3 dietary patterns: "Korean" diet (rice, vegetables, and Kimchi), "Western" diet (soda, eggs, and oil), and "New" diet (low sugar and high fruit and dairy product intakes). Compared to 1998, approximately 40% of participants still followed a Korean diet in 2010. Interestingly, the popularity of the Western diet fell by approximately 20%, whereas the new diet pattern increased 2-fold over the study period. Overall, these data show secular trends in dietary patterns that included a preservation of the traditional Korean diet and the emergence of a new diet pattern, and it demonstrated a unique transition in food and nutrient intakes in Korea.

The Korean Heart Study: rationale, objectives, protocol, and preliminary results for a new prospective cohort study of 430,920 men and women.

BACKGROUND: To describe the rationale, objectives, protocol, and preliminary results for a new prospective cohort study of cardiovascular disease (CVD) risk factors in South Korea. METHODS: Study members were recruited from participants in routine health assessments at health promotion centres across South Korea. Established and emerging CVD risk factors were measured. Eighteen centres holding electronic health records agreed to linkage of participants' records to future health insurance claims for monitoring of disease events. The recruitment of 430,920 participants (266,782 men, 164,138 women), aged 30-74 years, provides broad geographical reach across South Korea. RESULTS: Risk factor prevalence was more favourable in women than men, and, in general, in the younger rather than older study members. There was also close similarity between the characteristics of the present sample and the Korean National Health and Nutrition Examination Survey. The expected associations between risk factors and both CVD and death were also apparent. CONCLUSIONS: Data from the present sample, based on data linkage, show close agreement with South Korea-wide surveys (for risk factor prevalence) and the extant literature (for risk factor associations). These findings gives confidence in future results anticipated from this cohort study of east Asians - a group that has been traditionally under-researched.

Prediction of Colorectal Cancer Risk Using a Genetic Risk Score: The Korean Cancer Prevention Study-II (KCPS-II).

Colorectal cancer (CRC) is among the leading causes of cancer deaths and can be caused by environmental factors as well as genetic factors. Therefore, we developed a prediction model of CRC using genetic risk scores (GRS) and evaluated the effects of conventional risk factors, including family history of CRC, in combination with GRS on the risk of CRC in Koreans. This study included 187 cases (men, 133; women, 54) and 976 controls (men, 554; women, 422). GRS were calculated with most significantly associated single-nucleotide polymorphism with CRC through a genomewide association study. The area under the curve (AUC) increased by 0.5% to 5.2% when either counted or weighted GRS was added to a prediction model consisting of age alone (AUC 0.687 for men, 0.598 for women) or age and family history of CRC (AUC 0.692 for men, 0.603 for women) for both men and women. Furthermore, the risk of CRC significantly increased for individuals with a family history of CRC in the highest quartile of GRS when compared to subjects without a family history of CRC in the lowest quartile of GRS (counted GRS odds ratio [OR], 47.9; 95% confidence interval [CI], 4.9 to 471.8 for men; OR, 22.3; 95% CI, 1.4 to 344.2 for women) (weighted GRS OR, 35.9; 95% CI, 5.9 to 218.2 for men; OR, 18.1, 95% CI, 3.7 to 88.1 for women). Our findings suggest that in Koreans, especially in Korean men, GRS improve the prediction of CRC when considered in conjunction with age and family history of CRC.

Adiponectin is Associated with Impaired Fasting Glucose in the Non-Diabetic Population.

OBJECTIVES: Adiponectin is strongly associated with diabetes in the Western population. However, whether adiponectin is independently associated with impaired fasting glucose (IFG) in the non-obese population is unknown. METHODS: The serum adiponectin, insulin resistance (IR), and waist circumference (WC) of 27,549 healthy Koreans were measured. Individuals were then classified into tertile groups by gender. IFG was defined as a fasting serum glucose of 100-125 mg/dL without diabetes. IR was calculated using the homeostasis model assessment of insulin resistance (HOMA-IR). The association of adiponectin and IFG was determined using logistic regression analysis. RESULTS: WC and adiponectin were associated with IFG in both men and women. However, the association of WC with IFG was attenuated in both men and women after adjustment for the HOMA-IR. Adiponectin was still associated with IFG after adjustment for and stratification by HOMA-IR in men and women. Strong combined associations of IR and adiponectin with IFG were observed in men and women. Multivariate adjusted odds ratios (ORs) (95% confidence interval [CI]) among those in the highest tertile of IR and the lowest tertile of adiponectin were 9.8 (7.96 to 12.07) for men and 24.1 (13.86 to 41.94) for women. CONCLUSION: These results suggest that adiponectin is strongly associated with IFG, and point to adiponectin as an additional diagnostic biomarker of IFG in the non-diabetic population.