Body mass index and risk of breast cancer molecular subtypes in Korean women: a case-control study.

BACKGROUND: Our main objective of this research was to analyze the effect of BMI on breast cancer risk according to various subtypes of breast cancer stratified with menopausal status. METHODS: By using a case-control study setting, we recruited a total of 16,190 female breast cancer patients aged between 35 and 80 years from 2003 to 2010. These breast cancer patients were then individually matched by age to control female group (1:2 ratios of cases and controls). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated via multivariable logistic regression by setting normal BMI range (18.5-22.9) as the reference group. RESULTS: In premenopausal women, the risk of breast cancer of triple-negative subtype increased (OR 1.60, 95% CI 1.27-2.02) in obese II (BMI ≥ 30) women and in underweight women, it was Luminal A (OR 1.24, 95% CI 1.06-1.45) and HER2 express subtype (OR 1.43, 95% CI 1.26-1.62) that showed increased risk of breast cancer. In postmenopausal women, Luminal A (OR 2.35, 95% CI 2.01-2.75), Luminal B HER2 negative (OR 1.81, 95% CI 1.46-2.25) and triple-negative subtype (OR 2.25, 95% CI 1.85-2.72) showed higher risk of breast cancer in obese II women. CONCLUSION: Our findings suggest that the effect of BMI on breast cancer differs according to various subtypes and hormone receptors and to menopausal status.

Sex-specific Associations Between Serum Hemoglobin Levels and the Risk of Cause-specific Death in Korea Using the National Health Insurance Service-National Health Screening Cohort (NHIS HEALS).

OBJECTIVES: The purpose of this study was to determine the associations between blood hemoglobin (Hgb) levels and the risk of death by specific causes. METHODS: Using the National Health Insurance Services-National Health Screening Cohort (n=487 643), we classified serum Hgb levels into 6 sex-specific groups. Cox regression analysis was used to analyze the associations between Hgb levels and the risk of cause-specific death. RESULTS: Hgb levels in male population showed a U-shaped, J-shaped, or inverse J-shaped association with the risk of death from ischemic heart disease, acute myocardial infarction, liver cancer, cirrhosis and chronic obstructive pulmonary disease (COPD) (all non-linear p<0.05; hazard ratio [HR]; 95% confidence interval [CI]) for the lowest and the highest Hgb levels for the risk of each cause of death in male population: HR, 1.14; 95% CI, 0.98 to 1.34; HR, 2.87; 95% CI, 1.48 to 5.57; HR, 1.16; 95% CI, 0.96 to 1.40; HR, 3.05; 95% CI, 1.44 to 6.48; HR, 1.36; 95% CI, 1.18 to 1.56; HR, 2.11; 95% CI, 1.05 to 4.26; HR, 3.64; 95% CI, 2.49 to 5.33; HR, 5.97; 95% CI, 1.44 to 24.82; HR, 1.62; 95% CI, 1.14 to 2.30; HR, 3.84; 95% CI, 1.22 to 12.13, respectively), while in female population, high Hgb levels were associated with a lower risk of death from hypertension and a higher risk of death from COPD (overall p<0.05; HR, 1.86; 95% CI, 1.29 to 2.67 for the lowest Hgb levels for hypertension; overall p<0.01, HR, 6.60; 95% CI, 2.37 to 18.14 for the highest Hgb levels for COPD). For the risk of lung cancer death by Hgb levels, a linear negative association was found in male population (overall p<0.01; the lowest Hgb levels, HR, 1.17; 95% CI, 1.05 to 1.33) but an inverse J-shaped association was found in female population (non-linear p=0.01; HR, 1.25; 95% CI, 0.96 to 1.63; HR, 2.58; 95% CI, 1.21 to 5.50). CONCLUSIONS: Both low and high Hgb levels were associated with an increased risk of death from various causes, and some diseases showed different patterns according to sex.

Blood Pressure and the Risk of Death From Non-cardiovascular Diseases: A Population-based Cohort Study of Korean Adults.

OBJECTIVES: The objective of this study was to assess the relationship between systolic and diastolic blood pressure (SBP, DBP) and the risk of death from specific causes other than cardiovascular diseases. METHODS: We calculated the risk of specific death by SBP and DBP categories for 506 508 health examinees in 2002-2003 using hazard ratios (HRs) and 95% confidence intervals (CIs) in a Cox proportional hazards model. RESULTS: Compared to normal levels (SBP <120 or DBP <90 mmHg), stage I systolic and diastolic hypertension (SBP 140-159, DBP 85- 89 mmHg, respectively) were associated with an increased risk of death from diabetes mellitus, alcoholic liver disease, and renal failure (HR, 1.83; 95% CI, 1.51 to 2.22; HR, 1.24; 95% CI, 1.06 to 1.46; HR, 2.30; 95% CI, 1.64 to 3.21; HR, 1.67; 95% CI, 1.27 to 2.20; HR, 1.99; 95% CI, 1.41 to 2.81; HR, 1.31; 95% CI, 0.99 to 1.73, respectively), but a decreased risk of death from intestinal pneumonia (HR, 0.64; 95% CI, 0.42 to 0.98; HR, 0.59; 95% CI, 0.39 to 0.91). Only stage II systolic hypertension (SBP ≥160 mmHg) was associated with an increased risk of death from pneumonia, liver cirrhosis, and intestinal ischemia (HR, 1.54; 95% CI, 1.19 to 1.98; HR, 1.46; 95% CI, 1.00 to 2.15; HR, 3.77; 95% CI, 1.24 to 11.40, respectively), and stage I and II diastolic hypertension (SBP 140-159 and ≥160 mmHg) were associated with an increased risk of death from intestinal ischemia (HR, 3.07; 95% CI, 1.27 to 7.38; HR, 4.39; 95% CI, 1.62 to 11.88, respectively). CONCLUSIONS: An increase in blood pressure levels may alter the risk of death from certain causes other than cardiovascular diseases, a well-known outcome of hypertension, although the mechanism of these associations is not well documented.