Jee-Jeon Yi

Sex-age-specific association of body mass index with all-cause mortality among 12.8 million Korean adults: a prospective cohort study

Background: Despite differences in body shape and adiposity characteristics according to sex and age, a single range of healthy weight [body mass index (BMI, kg/m2) of 18.5–24.9) regardless of sex and age has been recommended. The aim of the study is to examine whether the association between BMI and all-cause mortality varies by sex and age, and, if relevant, to estimate sex-age-specific optimal BMIs associated with a minimal risk of death. Methods: A total of 12 832 637 Korean adults aged 18–99 years who participated in health examinations during 2001–04 were followed up until 2013. Hazard ratios of death in sex-age groups were calculated using Cox regression models after adjustment for age, smoking status and known pre-existing illness. Results: During follow-up, 456 175 men and 241 208 women died. Among men, the age-specific optimal BMI was 23.0–25.9 (kg/m2) at 18–34 years, 24.0–27.9 at 45–54 year, and 25.0–28.9 at 65–74 years. Among women, it was 15.5–24.9 at 18–34 years, 21.0–26.9 at 45–54 years and 24.0–28.9 at 65–74 years. Patterns of sex-age-specific association generally did not differ between never-smokers with no known illness and all participants. Progressively increased risks above and below sex-age-specific optimums were observed (reverse J-curve). Smoking had a limited impact on the observed associations. Conclusions: Women had a lower optimal BMI than men, especially at younger ages. The optimal BMI increased with age. Change in optimal BMI with age, however, was more profound in women than in men. Sex-age-specific optimums were generally higher than the current normal weight (BMI of 18.5–24.9), except in women below 50 years. Sex-age-specific guidelines related to body weight may be needed to guide people for better health.

Agent Orange exposure and disease prevalence in Korean Vietnam veterans: The Korean veterans health study

Between 1961 and 1971, military herbicides were used by the United States and allied forces for military purposes. Agent Orange, the most-used herbicide, was a mixture of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid, and contained an impurity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Many Korean Vietnam veterans were exposed to Agent Orange during the Vietnam War. The aim of this study was to evaluate the association between Agent Orange exposure and the prevalence of diseases of the endocrine, nervous, circulatory, respiratory, and digestive systems. The Agent Orange exposure was assessed by a geographic information system-based model. A total of 111,726 Korean Vietnam veterans were analyzed for prevalence using the Korea National Health Insurance claims data from January 2000 to September 2005. After adjusting for covariates, the high exposure group had modestly elevated odds ratios (ORs) for endocrine diseases combined and neurologic diseases combined. The adjusted ORs were significantly higher in the high exposure group than in the low exposure group for hypothyroidism (OR=1.13), autoimmune thyroiditis (OR=1.93), diabetes mellitus (OR=1.04), other endocrine gland disorders including pituitary gland disorders (OR=1.43), amyloidosis (OR=3.02), systemic atrophies affecting the nervous system including spinal muscular atrophy (OR=1.27), Alzheimer disease (OR=1.64), peripheral polyneuropathies (OR=1.09), angina pectoris (OR=1.04), stroke (OR=1.09), chronic obstructive pulmonary diseases (COPD) including chronic bronchitis (OR=1.05) and bronchiectasis (OR=1.16), asthma (OR=1.04), peptic ulcer (OR=1.03), and liver cirrhosis (OR=1.08). In conclusion, Agent Orange exposure increased the prevalence of endocrine disorders, especially in the thyroid and pituitary gland; various neurologic diseases; COPD; and liver cirrhosis. Overall, this study suggests that Agent Orange/2,4-D/TCDD exposure several decades earlier may increase morbidity from various diseases, some of which have rarely been explored in previous epidemiologic studies.

Agent Orange Exposure and Prevalence of Self-reported Diseases in Korean Vietnam Veterans

Objectives The aim of this study was to evaluate the association between Agent Orange exposure and self-reported diseases in Korean Vietnam veterans. Methods A postal survey of 114 562 Vietnam veterans was conducted. The perceived exposure to Agent Orange was assessed by a 6-item questionnaire. Two proximity-based Agent Orange exposure indices were constructed using division/brigade-level and battalion/company-level unit information. Adjusted odds ratios (ORs) for age and other confounders were calculated using a logistic regression model. Results The prevalence of all self-reported diseases showed monotonically increasing trends as the levels of perceived self-reported exposure increased. The ORs for colon cancer (OR, 1.13), leukemia (OR, 1.56), hypertension (OR, 1.03), peripheral vasculopathy (OR, 1.07), enterocolitis (OR, 1.07), peripheral neuropathy (OR, 1.07), multiple nerve palsy (OR, 1.14), multiple sclerosis (OR, 1.24), skin diseases (OR, 1.05), psychotic diseases (OR, 1.07) and lipidemia (OR, 1.05) were significantly elevated for the high exposure group in the division/brigade-level proximity-based exposure analysis, compared to the low exposure group. The ORs for cerebral infarction (OR, 1.08), chronic bronchitis (OR, 1.05), multiple nerve palsy (OR, 1.07), multiple sclerosis (OR, 1.16), skin diseases (OR, 1.05), and lipidemia (OR, 1.05) were significantly elevated for the high exposure group in the battalion/company-level analysis. Conclusions Korean Vietnam veterans with high exposure to Agent Orange experienced a higher prevalence of several self-reported chronic diseases compared to those with low exposure by proximity-based exposure assessment. The strong positive associations between perceived self-reported exposure and all self-reported diseases should be evaluated with discretion because the likelihood of reporting diseases was directly related to the perceived intensity of Agent Orange exposure.

BMI and All-Cause Mortality in Normoglycemia, Impaired Fasting Glucose, Newly Diagnosed Diabetes, and Prevalent Diabetes: A Cohort Study

OBJECTIVE This study examined associations between BMI and mortality in individuals with normoglycemia, impaired fasting glucose (IFG), newly diagnosed diabetes, and prevalent diabetes and identified BMI ranges associated with the lowest mortality in each group. RESEARCH DESIGN AND METHODS A total of 12,815,006 adults were prospectively monitored until 2013. Diabetes status was defined as follows: normoglycemia (fasting glucose <100 mg/dL), IFG (100–125 mg/dL), newly diagnosed diabetes (≥126 mg/dL), and prevalent diabetes (self-reported). BMI (kg/m2) was measured. Cox proportional hazards model hazard ratios were calculated after adjusting for confounders. RESULTS During a mean follow-up period of 10.5 years, 454,546 men and 239,877 women died. U-shaped associations were observed regardless of diabetes status, sex, age, and smoking history. Optimal BMI (kg/m2) for the lowest mortality by group was 23.5–27.9 (normoglycemia), 25–27.9 (IFG), 25–29.4 (newly diagnosed diabetes), and 26.5–29.4 (prevalent diabetes). Higher optimal BMI by worsening diabetes status was more prominent in younger ages, especially in women. The relationship between worsening diabetes status and higher mortality was stronger with lower BMI, especially at younger ages. Given the same BMI, people with prevalent diabetes had higher mortality compared with those with newly diagnosed diabetes, and this was more striking in women than men. CONCLUSIONS U-curve relationships existed regardless of diabetes status. Optimal BMI for lowest mortality became gradually higher with worsening diabetes for each sex and each age-group.

Low Systolic Blood Pressure and Vascular Mortality Among More Than 1 Million Korean Adults

Background— The association between low systolic blood pressure (SBP) and vascular disease is unclear, especially in nonclinical populations. Methods and Results— We studied 1 235 246 individuals who participated in routine medical examinations between 1992 and 1995. The hazard ratios (HRs) were adjusted for potential confounders. During 22.7 million person-years of follow-up, 34 816 individuals died of atherosclerotic vascular diseases. An increase in SBP was directly related to an increase in vascular mortality at SBP above ≈100 mmHg. The group with the lowest SBP (<90 mm Hg) had a higher HR for mortality from atherosclerotic vascular disease (HR, 1.53; 95% confidence interval, 1.15–2.03) in comparison with those with an SBP of 90 to 99 mm Hg. The HR associated with the lowest SBP was 2.54 (95% confidence interval, 1.51–4.29) for ischemic heart disease and 1.21 (95% confidence interval, 0.79–1.85) for stroke. Regarding stroke subtype, mortality from hemorrhagic stroke (HR per 10 mm Hg increase, 0.53; 95% confidence interval, 0.29–0.96), rather than mortality from ischemic stroke (HR per 10 mm Hg increase, 1.00; 95% confidence interval, 0.51–1.97), was inversely associated with SBP when SBP fell to <100 mm Hg. Even when excluding the first 5 years of follow-up, the HRs associated with the lowest SBP did not decrease. The inverse association between SBP and vascular mortality in the range <100 mm Hg tended to be apparent in people aged 60 to 95 years in comparison with individuals aged 30 to 59 years. Conclusions— J-curve associations exist between SBP and vascular mortality, which reach a nadir at ≈100 mm Hg. SBP of <90 mm Hg may portend death from vascular disease, particularly from ischemic heart disease.

Body Mass Index and Cancer Mortality Among Korean Older Middle-Aged Men: A Prospective Cohort Study.

AbstractThe association of body mass index (BMI; kg/m2) with overall and site-specific cancer mortality in Asians is not well understood. A total of 113,478 men from the Korean Veterans Health Study who returned a postal survey in 2004 were followed up until 2010. The adjusted hazard ratios (HRs) of cancer mortality were calculated using a Cox model. During 6.4 years of follow-up, 3478 men died from cancer. A reverse J-curve association with a nadir at 25.0 to 27.4 kg/m2 was observed. Below 25 kg/m2, the HRs of death for each 5 kg/m2 decrease in BMI were 1.72 (95% confidence interval = 1.57–1.90) for overall cancer; 3.63 (2.57–5.12) for upper aerodigestive tract (UADT) cancers, including oral cavity and larynx [HR = 4.21 (2.18–8.12)] and esophagus [HR = 2.96 (1.82–4.81)] cancers; 1.52 (1.35–1.71) for non-UADT and non-lung cancers, including stomach [HR = 2.72 (2.13–3.48)] and large intestine [HR = 1.68 (1.20–2.36)] cancers; and 1.93 (1.59–2.34) for lung cancer. In the range of 25 to 47 kg/m2, the HRs for each 5 kg/m2 increase in BMI were 1.27 (1.03–1.56) for overall cancer mortality and 1.57 (1.02–2.43) for lung cancer mortality. In individuals <25 kg/m2, inverse associations with mortality from overall cancer and non-UADT and non-lung cancer were stronger in never-smokers than in current smokers. Both low and high BMI were strong predictors of mortality from overall and several site-specific cancers in Korean men. Further research is needed to evaluate whether interventions involving weight change (loss or gain) reduce the risk of cancer or improve the survival.

Impact of alcohol consumption and body mass index on mortality from nonneoplastic liver diseases, upper aerodigestive tract cancers, and alcohol use disorders in Korean older middle-aged men: Prospective cohort study.

AbstractAlcohol use is a leading risk factor for the global disease burden including liver diseases. However, the combined effect of alcohol use and body mass index (BMI) on alcohol-related diseases has seldom been examined. We examined whether alcohol consumption and BMI could act together to increase mortality from nonneoplastic liver diseases, upper aero-digestive tract (UADT) cancers, and alcohol use disorders (AUD) in middle-aged Korean men.107,735 men (mean age, 58.8 years) participated in a postal survey in 2004 and were followed until 2010, by linkage to national death records. Hazard ratios (HRs) of cause-specific death were calculated after adjustment for confounders.Each 5-drink (approximately 45 g alcohol) higher weekly alcohol consumption was associated with increased mortality, by approximately 70% for nonneoplastic liver disease mortality (HR = 1.70, P < 0.001), approximately 60% for UADT cancer mortality (HR = 1.64, P < 0.001), and approximately 70% for AUD mortality (HR = 1.71, P < 0.001). Generally, BMI was inversely associated with these alcohol-related diseases (HR per each 5 kg/m2 higher BMI = 0.18-0.46, P < 0.001 for each cause), while, in participants with BMI ≥25 kg/m2, each 5 kg/m2 higher BMI was also associated with an elevated mortality from nonneoplastic liver diseases of approximately 150% (HR = 2.52, P = 0.001). Men with BMI < 21 kg/m2 and weekly alcohol consumption ≥14 drinks showed markedly higher mortality from nonneoplastic liver diseases (HR = 5.7), alcoholic liver diseases (HR = 9.3), UADT cancers (HR = 10.5), and esophageal cancer (HR = 15.5), compared to men drinking less than 1 drink/wk with BMI ≥25 kg/m2. The combined effect of low BMI and high weekly alcohol consumption was 2.25- to 3.29-fold greater than the additive effect of each factor for these alcohol-related diseases (P < 0.05 for each cause).Alcohol consumption and low BMI were related to deaths from nonneoplastic liver diseases, UADT cancers, and AUD, with evidence of a supra-additive combined effect of both factors. High BMI was also related to deaths from nonneoplastic liver diseases. Men with a low BMI (<23 kg/m2) are suggested to be prone to the harmful effects of alcohol.

Association between fasting glucose and all-cause mortality according to sex and age: a prospective cohort study

The association of fasting glucose with the risk of death according to sex and age remains unclear, and insufficient information is available on sex- and age-specific glucose concentrations within ethnic groups. This study analyzed a sample of 12,455,361 Korean adults who participated in health examinations during 2001–2004, and were followed up until 2013. Men had 3.0 mg/dL (0.167 mmol/L) higher mean glucose concentrations than women (94.7 vs. 91.7 mg/dL), although women over 73 years had higher levels. For glucose levels of 100–199 mg/dL, each 18 mg/dL (1 mmol/L) increase in fasting glucose increased mortality by 13% (HR = 1.13, [95% CI 1.12 to 1.13], p < 0.001). In individuals with fasting glucose levels of 100–125 mg/dL, each 18 mg/dL increase in fasting glucose was associated with a 30% increase in the risk for mortality (1.30, [1.18 to 1.43]) in those aged 18–34 years, a 32% increase (1.32, [1.26 to 1.39]) in those aged 35–44 years, and a 10% increase (1.10, [1.02 to 1.19]) in those aged 75–99 years. The fasting glucose levels associated with the lowest mortality were 80–94 mg/dL regardless of sex and age. Prediabetes (100–125 mg/dL) was associated with higher mortality. The associations of hyperglycemia with mortality were stronger at younger ages.

Fasting Glucose and All-Cause Mortality by Age in Diabetes: A Prospective Cohort Study

OBJECTIVE To examine associations between fasting glucose and mortality and to identify the levels associated with lowest mortality by age in diabetes. RESEARCH DESIGN AND METHODS A total of 359,645 Korean adults with known prevalent diabetes participated in health screening during 2001–2004 and were followed up until 2013. RESULTS U-curve associations were found. Fasting glucose levels associated with the lowest mortality were ∼90–130 mg/dL, except for in those aged 18–44 years (∼80–95 mg/dL). Multivariable-adjusted hazard ratios of fasting glucose <65, 65–74, 75–84, 140–169, 170–199, and ≥200 mg/dL were 1.46, 1.12, 1.09, 1.12, 1.31, and 1.78, respectively, compared with 85–99 mg/dL. CONCLUSIONS Optimal fasting glucose range for survival is higher in adults with than without known prevalent diabetes, except, perhaps, younger adults. Tight glucose control may lessen premature death in younger adults with diabetes. Hypoglycemia (<65 mg/dL) was associated with higher mortality than was fasting glucose 170–199 mg/dL, while fasting glucose 65–84 mg/dL had risks comparable with those at levels 140–169 mg/dL in diabetes.

Body mass index and gastrointestinal cancer mortality in Korean adults: A prospective cohort study: Body mass index and digestive cancer

The association between body mass index (BMI) and mortality from gastrointestinal (GI) cancer remains unclear, especially in Asian populations.