Jae-Hong Ryoo

Clinical availability of nonalcoholic fatty liver disease as an early predictor of type 2 diabetes mellitus in korean men: 5‐year prospective cohort study

There have been several reports about the clinical association between type 2 diabetes mellitus (DM) and nonalcoholic fatty liver disease (NAFLD). However, most of the studies were about the unilateral effects of type 2 DM on NAFLD, and studies on the reverse relation are rare. Thus, this study was designed to investigate the effect of NAFLD on type 2 DM. We conducted a prospective cohort study on 25,232 Korean men without type 2 DM for 5 years. We serially checked the various metabolic factors including fasting glucose and hemoglobin A1c (HbA1c), and monitored the development of type 2 DM. The incidence rate of type 2 DM was compared according to the degree of NAFLD (normal, mild, and moderate to severe), and a Cox proportional hazards model was used to measure the hazard ratios (HRs) of NAFLD on type 2 DM. The incidence rate of type 2 DM increased according to the degree of NAFLD (normal: 7.0%, mild: 9.8%, moderate to severe: 17.8%, P < 0.001). Even after adjusting for other multiple covariates, the HRs (95% confidence interval [CI]) for type 2 DM development was higher in the mild group (1.09; 0.81‐1.48) and moderate to severe group (1.73; 1.00‐3.01) compared to the normal group, respectively (P for trend <0.001). Conclusion: The development of type 2 DM is potentially more associated with more progressive NAFLD than a normal or milder state. In addition, NAFLD was an independent risk factor for the future development of type 2 DM. These results suggest the potential availability of NAFLD as an early predictor of type 2 DM. (HEPATOLOGY 2013;57:1378–1383)

Clinical association between non-alcoholic fatty liver disease and the development of hypertension.

Non‐alcoholic fatty liver disease (NAFLD) is getting an increasing attention for its clinical implications on cardiovascular disease (CVD). However, epidemiologic data are not so evident to sustain the causative association between NAFLD and hypertension, the major cause of CVD. Accordingly, we designed this study to investigate the clinical association between NAFLD and the development of hypertension.

The clinical availability of non alcoholic fatty liver disease as an early predictor of the metabolic syndrome in Korean men: 5-Year's prospective cohort study

OBJECTIVES There were many studies for the clinical association between non alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS). However, while most of studies have focused on the unilateral effects of MetS on NAFLD, studies for reverse association were comparatively rare. Therefore, we carried out a prospective cohort study to evaluate the longitudinal effects of NAFLD on the development of MetS according to the degree of NAFLD. PATIENTS AND METHODS A total of 46,874 men, who had participated in a medical health check-up program in 2005, were enrolled in this study. Out of them, a Mets-free cohort of 11,926 without excluding conditions was followed up until 2010. All participants were classified into 3 groups by their NAFLD status (normal, mild, moderate to severe). The baseline values of metabolic components and the development rates of MetS were compared according to the degree of NAFLD. Cox proportional hazards model was used to measure the hazard ratios (HRs) for MetS according to the degree of NAFLD. RESULTS During 41,912.1 person-years of follow-up, 1861 incident cases of MetS developed between 2006 and 2010. Even after adjusting for multiple covariates, the HRs (95% CI) for MetS were higher in the mild group (1.49; 1.30-1.70) and moderate to severe group (2.00; 1.46-2.73) compared to normal group, respectively (P for trend <0.001). These associations were apparent in the clinically relevant subgroup analyses. CONCLUSIONS NAFLD was independent risk factor for MetS during the 5-yr follow-up period.

Association of apolipoprotein B and incidence of metabolic syndrome in Korean men: A 5-years' follow-up study

BACKGROUND AND OBJECTIVE There have been reports for the association between elevated serum apolipoprotein B (ApoB) and several cardiometabolic disorders. However, it remains unclear whether serum ApoB level predicts the development of metabolic syndrome (MetS). Accordingly, we carried out a prospective study to evaluate the longitudinal effects of baseline serum ApoB levels on the development of MetS. PATIENTS AND METHODS A cohort of 25,193 healthy Korean men without MetS had been followed up prospectively. Baseline serum ApoB levels were categorized to following quintiles (quintile 1-5: <76.4, 76.4-88.4, 88.4-99.5, 99.5-113.0, ≥113.0). We evaluated the differences in the incidence of MetS according to quintiles of serum ApoB levels. Cox proportional hazards models were used to calculate the adjusted hazard ratios (HRs) for MetS. RESULTS During follow-up, 5407 (21.5%) cases developed MetS between 2006 and 2010. Incidence of MetS increased according to quintiles of serum ApoB levels [quintile 1-5: 9.1%, 16.4%, 22.1%, 27.3%, 36.4%, respectively (P for trend <0.001)]. Even after adjusting for various covariates including non-HDL-cholesterol, the hazard ratios (95% CI) for MetS increased in proportion to the quintiles of serum ApoB levels, compared to quintile 1 [quintile 2-5: 1.64 (1.43-1.89), 1.98 (1.71-2.31), 2.32 (1.96-2.75) and 2.92 (2.37-3.60), respectively (P for trend <0.001)]. These associations were apparent still in the clinically relevant subgroup analyses. CONCLUSIONS Serum ApoB levels predict MetS, independent of baseline confounding variables including non-HDL-cholesterol.

Serum uric acid level is associated with the development of microalbuminuria in Korean men

Elevated serum uric acid (UA) could be a risk factor for hypertension, type 2 diabetes mellitus and cardiovascular disease. In addition, elevated serum UA may be associated with impaired renal function. However, it is unclear whether elevated serum UA is a cause of microalbuminuria or not. Therefore, we performed a prospective cohort study of the temporal relationship between baseline elevated serum UA and the development of microalbuminuria in Korean men.

Clinical association between serum γ-glutamyltransferase levels and the development of insulin resistance in Korean men: a 5-year follow-up study

In recent years, γ‐glutamyltransferase has emerged as a predictor of cardiovascular disease, Type 2 diabetes mellitus, the metabolic syndrome and hypertension. However, it is not yet certain whether γ‐glutamyltransferase is a predictor for insulin resistance. The aim of this study was to examine the longitudinal association between baseline γ‐glutamyltransferase level and the development of insulin resistance in Korean men.

Serum Uric Acid Level and the Incidence of Metabolic Syndrome in Middle-aged Korean Men: A 5-Year Follow-up Study

Objectives: Elevated serum uric acid (UA) has been known to be associated with the prevalence of metabolic syndrome (MetS). However, no prospective studies have examined whether serum UA levels are actually associated with the development of MetS. We performed a prospective study to evaluate the longitudinal effects of baseline serum UA levels on the development of MetS. Methods: A MetS-free cohort of 14 906 healthy Korean men, who participated in a medical check-up program in 2005, was followed until 2010. MetS was defined according to the Joint Interim Statement of the International Diabetes Federation Task Force on Epidemiology and Prevention. Cox proportional hazards models were performed. Results: During 52 466.1 person-years of follow-up, 2428 incident cases of MetS developed between 2006 and 2010. After adjusting for multiple covariates, the hazard ratios (95% confidence intervals) for incident MetS for the second, the third, and the fourth quartile to the first quartile of serum UA levels were 1.09 (0.92-1.29), 1.22 (1.04-1.44), and 1.48 (1.26-1.73), respectively (p for trend <0.001). These associations were also significant in the clinically relevant subgroup analyses. Conclusions: Elevated serum UA levels were independently associated with future development of MetS in Korean men during the 5-year follow-up period.

Clinical significance of non-alcoholic fatty liver disease as a risk factor for prehypertension.

Previous epidemiologic studies have shown the clinical association between non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease (CVD). However, there is only limited information about the effect of NAFLD on the development of hypertension. Accordingly, we investigated the clinical association between NAFLD and prehypertension. A prospective cohort study was conducted on the 11,350 Korean men without prehypertension for 5 yr. The incidences of prehypertension were evaluated, and Cox proportional hazard model was used to measure the hazard ratios (HRs) for the development of prehypertension according to the degree of NAFLD (normal, mild, moderate to severe). The incidence of prehypertension increased according to NAFLD states (normal: 55.5%, mild: 63.7%, moderate to severe: 70.3%, P<0.001). Even after adjusting for multiple covariates, the HRs (95% confidence interval) for prehypertension were higher in the mild group (1.18; 1.07-1.31) and moderate to severe group (1.62; 1.21-2.17), compared to normal group, respectively (P for trend <0.001). The development of prehypertension is more potentially associated with the more progressive NAFLD than normal and milder state. These findings suggest the clinical significance of NAFLD as one of risk factors for prehypertension.

The clinical importance of serum γ-glutamyltransferase level as an early predictor of obesity development in Korean men

BACKGROUND AND OBJECTIVE Serum γ-glutamyl transferase (GGT) levels are known to be positively associated with obesity. We aimed at verifying an association between baseline GGT levels and the development of obesity in Korean men. PATIENTS AND METHODS This prospective cohort study was performed on 18,510 initially non-obese Korean men. The total follow-up period was 66,993.3 person years and the average follow-up period was 3.62 years (standard deviation [SD], 1.44). Cox proportional hazards model was used to determine hazard ratios for the risk of obesity development. RESULTS We found a strong positive association between serum GGT levels at baseline and obesity development, after adjusting for multiple covariates. The risk of obesity development was found to be significantly and dose-dependently associated with serum GGT level. Moreover, estimated hazard ratios for severe obesity (BMI (body mass index) ≥30 kg/m(2)) attributable to serum GGT levels were much higher than those for obesity (BMI ≥ 25 kg/m(2)). The significant association was also found for WC (waist circumference)-defined obesity (WC > 90 cm). CONCLUSIONS Our findings, which were obtained from a large cohort, indicate that serum GGT is an early predictor of obesity development. Furthermore, this association was remained significant after adjusting for multiple baseline covariates.

Association of Serum γ-Glutamyltransferase Level and Incident Prehypertension in Korean Men

Several lines of evidence indicate that prehypertension is more atherogenic than normal blood pressure. Serum γ-glutamyltransferase (GGT) is known to be positively associated with prehypertensive status and the progression of hypertension. However, there have been no prospective studies of serum GGT level as a predictor of prehypertension. Apparently 13,435 healthy men (mean age 42.0 ± 6.6 yr) with normal blood pressure were included in a prospective cohort study in 2005 and were followed up to 2010 with the endpoint being incident of prehypertension. During the follow up period (median 2.80 ± 1.44 yr; actual follow-up 37,679.1 person-year), prehypertension was developed in 7,867 (58.6%) participants. Risk estimations for incident prehypertension were analyzed based on quartiles of serum GGT levels using multivariate adjusted Cox proportional hazards model. In unadjusted model, the hazard ratio for incident prehypertension for the highest 3 quartiles of baseline serum GGT level was 1.21 (1.13-1.29), 1.29 (1.21-1.38), and 1.57 (1.47-1.67) compared the lowest quartile of serum GGT level, respectively (P for trend < 0.001). These associations still remained statistically significant, even after adjusting for multiple covariates. These findings indicate that increased serum GGT level is independently associated with incident prehypertension in Korean men.