Relationship of three different types of low-carbohydrate diet to cardiometabolic risk factors in a Japanese population: the INTERMAP/INTERLIPID Study.

PURPOSE: Low-carbohydrate diets (LCD) are a popular dietary strategy for weight reduction. The effects of LCD on long-term outcome vary depending on type of LCD, possibly due to the fact that effects on cardiometabolic risk factors may vary with different types of LCD. Accordingly, we studied these relations. METHODS: We assessed serum concentrations of high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), high-sensitivity C-reactive protein (CRP), total cholesterol, glycated hemoglobin, and uric acid, and nutrient intakes by standardized methods in men and women ages 40-59 years from four population samples of Japanese in Japan (553 men and 544 women, combined). For people consuming usual, animal-based, and plant-based LCDs, we calculated LCD scores, based on relative level of fat, protein, and carbohydrate, by modifying the methods of Halton et al. Instead of calculating scores based on animal or vegetable fat, we used saturated fatty acids (SFA) or monounsaturated fatty acids (MUFA) + polyunsaturated fatty acids (PUFA). RESULTS: In multivariate regression analyses with adjustment for site, age, sex, BMI, smoking, alcohol intake, physical activity, and years of education, all three LCD scores were significantly positively related to HDLc (all P < 0.001), but not to LDLc. The plant-based LCD score was significantly inversely related to log CRP (coefficient = -0.010, P = 0.018). CONCLUSIONS: All three LCD scores were significantly positively related to HDLc. The plant-based LCD score was significantly inversely related to CRP. Carbohydrate intake below 50 % of total energy with higher intakes of vegetable protein and MUFA + PUFA, and lower intakes of SFA may be favorable for reducing cardiometabolic risk factors.

High long-chain n-3 fatty acid intake attenuates the effect of high resting heart rate on cardiovascular mortality risk: a 24-year follow-up of Japanese general population.

BACKGROUND: Increased resting heart rate (RHR) independently predicts cardiovascular mortality. Meanwhile, long-chain n-3 fatty acids (LCn3FAs) have a cardioprotective effect. Our aim was to evaluate whether higher LCn3FAs intake attenuates the elevated risk of cardiovascular mortality associated with increased RHR. METHODS: We conducted a population-based 24-year prospective cohort study of Japanese, whose LCn3FAs intake is relatively high. Study participants included 8807 individuals aged 30-95 years from randomly selected areas across Japan without cardiovascular diseases and anti-hypertensive drugs at baseline. The primary endpoint was cardiovascular mortality, and the secondary endpoints were cardiac and stroke mortality during 24 years of follow-up. Individual dietary LCn3FAs intake was estimated from household-based 3-day weighed food records. RHR was obtained from 3 consecutive R-wave intervals on 12-lead electrocardiography. Cox models were used to estimate the multivariable hazard ratios (HRs) and 95% confidence intervals (95% CIs) adjusting for possible confounders. RESULTS: During the follow-up period, 617 cardiovascular deaths were observed. The median daily intake of LCn3FAs was 0.37% kcal (0.86g/day). The interaction between dietary LCn3FAs intake and RHR in the risk of cardiovascular mortality was statistically significant (p=0.033). The risk of cardiovascular mortality was significantly higher in the low-intake group (<0.37%kcal) with an RHR >85beats/min (bpm) [hazard ratio (HR), 1.67; 95% confidence interval (CI), 1.15-2.43], but not in the high-intake group (≥0.37%kcal) with an RHR >85bpm (HR, 0.92; 95% CI, 0.61-1.38), compared with those in the high-intake group with an RHR <70bpm. Similar results were observed with stroke mortality, but not with cardiac mortality. CONCLUSIONS: The risk of cardiovascular mortality associated with increased RHR is elevated in participants with low dietary LCn3FAs intake, but not in participants with high dietary LCn3FAs intake in a representative Japanese general population. These results suggest that high dietary LCn3FAs intake may prevent cardiovascular mortality associated with increased RHR.

Interaction between dietary marine-derived n-3 fatty acids intake and J-point elevation on the risk of cardiac death: a 24-year follow-up of Japanese men.

OBJECTIVE: Higher marine-derived n-3 fatty acids (MDn3FAs) intake reduces the risk of sudden cardiac death via antiarrhythmic effects. The article evaluates whether MDn3FAs intake attenuates the increased risk of cardiac death associated with J-point elevation (JPE), characterised by an elevation of QRS-ST junction (J-point) ≥0.1 mV on electrocardiography. DESIGN: A prospective population-based cohort study. SETTING: The National Survey on Circulatory Disorders and the National Nutrition Survey of Japan. PARTICIPANTS: A total of 4348 community-dwelling men (mean age 49.3 years), without cardiovascular diseases at baseline, from randomly selected areas across Japan. MAIN OUTCOME MEASURES: Cardiac death (200 men) during the 24-year follow-up. RESULTS: Dietary MDn3FAs intake was assessed using a dietary method to estimate individual intake of household-based weighed food records for 3 days. Cox models were used to calculate HRs and 95% CIs adjusted for possible confounding factors. JPE was present in 340 participants (7.8%). The median daily intake of MDn3FAs was 0.35%kcal (0.92 g/day). The risk of cardiac death was significantly higher in participants with JPE than in those without JPE in the low intake group (<0.35%kcal; adjusted HR 3.51; 95% CI 1.84 to 6.73; p<0.001), but not in the high intake group (≥0.35%kcal; adjusted HR 1.09; 95% CI 0.56 to 2.16; p=0.795). The interaction between dietary MDn3FAs intake and JPE on the risk of cardiac death was statistically significant (p=0.006). CONCLUSIONS: The increased risk of cardiac death associated with JPE may be attenuated by higher dietary MDn3FAs intake.

Intake of folate, vitamin B6 and vitamin B12 and the risk of CHD: the Japan Public Health Center-Based Prospective Study Cohort I.

OBJECTIVE: To investigate the association of dietary folate, vitamin B(6) (VB(6)) and vitamin B(12) (VB(12)) with the risk of coronary heart disease among middle-aged persons. METHODS: A total of 40,803 subjects aged 40-59 years living in the community who were free of prior diagnoses of cardiovascular disease and cancer and who completed a food frequency questionnaire were followed from 1990-1992 to the end of 2001 in the Japan Public Health Center-based Prospective Study. RESULTS: After 468,472 person-years of follow-up, 251 coronary heart disease incidents were documented. Coronary heart disease and definite myocardial infarction were inversely associated with dietary intake of folate, VB(6) and VB(12) after adjustment for age and sex, but the associations were attenuated after further adjustment for smoking, dietary and other cardiovascular risk factors. However, among non-multivitamin supplement users, multivariable hazard ratios (95% confidence intervals) in the highest vs. lowest quintiles of VB(6) intake were 0.60 (0.37-0.97) for total coronary heart disease and 0.52 (0.29-0.91) for definite myocardial infarction, and the inverse associations with VB(12) were marginally significant. The combination of below-median intake of three vitamins or of only B(6) conferred a twice excess risk of total coronary heart disease. CONCLUSIONS: Dietary intake of VB(6) was associated with a reduced risk of coronary heart disease among middle-aged non-multivitamin supplement users. Dietary folate and VB(12) were also suggested to be protective factors for coronary heart disease.

Effect of combined cardiovascular risk factors on individual and population medical expenditures: a 10-year cohort study of national health insurance in a Japanese population.

BACKGROUND: Although obesity is required for some criteria defining metabolic syndrome, clustering of other risk factors also indicates an increased risk of cardiovascular disease. Whether the relationship between cardiovascular risk factor clustering and medical expenditures differs with body mass index (BMI) requires investigation, especially in a population with a low prevalence of obesity such as that in Japan. METHODS AND RESULTS: A 10-year cohort study of 4,478 Japanese National Health Insurance beneficiaries aged 40-69 years in a community between 1990 and 2001 was carried out in the present study. The clustering of cardiovascular risk factors showed a positive and graded relationship to personal medical expenditures in participants who are overweight (BMI > or =25.0) and normal weight (BMI <25.0). The individual medical expenditures per month were 1.7-fold higher for participants with 2 or 3 risk factors and overweight than for those without these factors (26,782 vs 15,377 Japanese yen). Differences in the geometric means were similarly significant after adjustment for other confounding factors. However, the excess medical expenditures by risk clustering of normal weight categories within the total medical expenditures were higher than those of overweight categories because more participants were of normal weight. CONCLUSIONS: Cardiovascular risk factor clustering and being overweight can be a useful predictor of medical expenditures in a Japanese population.

Intake of fish and n3 fatty acids and risk of coronary heart disease among Japanese: the Japan Public Health Center-Based (JPHC) Study Cohort I.

BACKGROUND: Once- or twice-weekly consumption of fish (or a small amount of fish intake) reduces the risk of coronary heart disease and sudden cardiac death in Western countries. It is uncertain whether a high frequency or large amount of fish intake, as is the case in Japan, further reduces the risk. METHODS AND RESULTS: To examine an association between high intake of fish and n3 polyunsaturated fatty acids and the risk of coronary heart disease, a total of 41,578 Japanese men and women aged 40 to 59 years who were free of prior diagnosis of cardiovascular disease and cancer and who completed a food frequency questionnaire were followed up from 1990-1992 to 2001. After 477,325 person-years of follow-up, 258 incident cases of coronary heart disease (198 definite and 23 probable myocardial infarctions and 37 sudden cardiac deaths) were documented, comprising 196 nonfatal and 62 fatal coronary events. The multivariable hazard ratios (HRs) and 95% confidence intervals in the highest (8 times per week, or median intake=180 g/d) versus lowest (once a week, or median intake=23 g/d) quintiles of fish intake were 0.63 (0.38 to 1.04) for total coronary heart disease, 0.44 (0.24 to 0.81) for definite myocardial infarction, and 1.14 (0.36 to 3.63) for sudden cardiac death. The reduced risk was primarily observed for nonfatal coronary events (HR=0.43 [0.23 to 0.81]) but not for fatal coronary events (HR=1.08 [0.42 to 2.76]). Strong inverse associations existed between dietary intake of n3 fatty acids and risk of definite myocardial infarction (HR=0.35 [0.18 to 0.66]) and nonfatal coronary events (HR=0.33 [0.17 to 0.63]). CONCLUSIONS: Compared with a modest fish intake of once a week or &20 g/d, a higher intake was associated with substantially reduced risk of coronary heart disease, primarily nonfatal cardiac events, among middle-aged persons.