Longitudinal associations between micronutrient consumption and leukocyte telomere length.

BACKGROUND: There are few studies on the association between nutrient intake and telomere length, which may reflect cumulative oxidative stress and indicate biological ageing. In the present study, we evaluated longitudinal associations between the consumption of micronutrients, including antioxidant nutrients and B vitamins involved in one-carbon transfer pathways, and leukocyte telomere length (LTL). METHODS: The study included 1958 middle-aged and older Korean men and women (age range at baseline: 40-69 years) from a population-based cohort. We collected dietary information at baseline using a semiquantitative food frequency questionnaire (June 2001 to January 2003) and assessed the consumption of micronutrients, including vitamins A, B1 , B2 , B3 , B6 , B9 (folate), C and E, as well as calcium, phosphorus, potassium, iron and zinc. We measured LTL using a real-time polymerase chain reaction at the 10-year follow-up examination (February 2011 to November 2012). RESULTS: In the multiple regression model adjusted for potential confounders, LTL was positively associated with the consumption of vitamin C (P < 0.05), folate (P = 0.05) and potassium (P = 0.05) in all participants. In the age-stratified analysis, the association between the consumption of vitamin C (P < 0.01), folate (P < 0.05) and potassium (P < 0.05) with LTL was significant only among participants aged <50 years. CONCLUSIONS: Our findings suggest that the earlier consumption of vitamin C, folate and potassium, which are abundant in fruits and vegetables, can delay biological ageing in middle-aged and older adults.

Association between dietary patterns in the remote past and telomere length.

BACKGROUND/OBJECTIVES: There are limited data on the association between dietary information and leukocyte telomere length (LTL), which is considered an indicator of biological aging. In this study, we aimed at determining the association between dietary patterns or consumption of specific foods and LTL in Korean adults. SUBJECT/METHODS: A total of 1958 middle-aged and older Korean adults from a population-based cohort were included in the study. Dietary data were collected from a semi-quantitative food frequency questionnaire at baseline (June 2001 to January 2003). LTL was assessed using real-time PCR during the 10-year follow-up period (February 2011 to November 2012). RESULTS: We identified two major factors and generated factor scores using factor analysis. The first factor labeled 'prudent dietary pattern' was characterized by high intake of whole grains, seafood, legumes, vegetables and seaweed, whereas the second factor labeled 'Western dietary pattern' was characterized by high intake of refined grain, red meat or processed meat and sweetened carbonated beverages. In a multiple linear regression model adjusted for age, sex, body mass index and other potential confounding variables, the prudent dietary pattern was positively associated with LTL. In the analysis of particular food items, higher consumption of legumes, nuts, seaweed, fruits and dairy products and lower consumption of red meat or processed meat and sweetened carbonated beverages were associated with longer LTL. CONCLUSIONS: Our findings suggest that diet in the remote past, that is, 10 years earlier, may affect the degree of biological aging in middle-aged and older adults.

Dietary information improves cardiovascular disease risk prediction models.

BACKGROUND/OBJECTIVES: Data are limited on cardiovascular disease (CVD) risk prediction models that include dietary predictors. Using known risk factors and dietary information, we constructed and evaluated CVD risk prediction models. SUBJECTS/METHODS: Data for modeling were from population-based prospective cohort studies comprised of 9026 men and women aged 40-69 years. At baseline, all were free of known CVD and cancer, and were followed up for CVD incidence during an 8-year period. We used Cox proportional hazard regression analysis to construct a traditional risk factor model, an office-based model, and two diet-containing models and evaluated these models by calculating Akaike information criterion (AIC), C-statistics, integrated discrimination improvement (IDI), net reclassification improvement (NRI) and calibration statistic. RESULTS: We constructed diet-containing models with significant dietary predictors such as poultry, legumes, carbonated soft drinks or green tea consumption. Adding dietary predictors to the traditional model yielded a decrease in AIC (delta AIC=15), a 53% increase in relative IDI (P-value for IDI <0.001) and an increase in NRI (category-free NRI=0.14, P <0.001). The simplified diet-containing model also showed a decrease in AIC (delta AIC=14), a 38% increase in relative IDI (P-value for IDI <0.001) and an increase in NRI (category-free NRI=0.08, P<0.01) compared with the office-based model. The calibration plots for risk prediction demonstrated that the inclusion of dietary predictors contributes to better agreement in persons at high risk for CVD. C-statistics for the four models were acceptable and comparable. CONCLUSIONS: We suggest that dietary information may be useful in constructing CVD risk prediction models.

Association of coronary artery calcification with obstructive sleep apnea and obesity in middle-aged men.

BACKGROUND AND AIMS: Obstructive sleep apnea (OSA) and obesity are closely associated, and both have been reported to increase the risk of coronary heart disease. Although obesity is known to be associated with coronary artery calcification (CAC), there is limited information on whether OSA is associated with CAC independent of obesity. METHODS AND RESULTS: A cross-sectional study examined the association between OSA and CAC among 258 healthy men, ages 40-49 years old, randomly selected from a population-based cohort. All individuals underwent overnight polysomnography and electron-beam computed tomography to measure their apnea-hypopnea index (AHI) and degree of CAC. A logistic regression model including potential cardiovascular risk factors excluding body mass index (BMI) showed that the presence of CAC was significantly greater in the fourth quartile versus the first quartile of AHI severity (odds ratio [OR] 2.21, 95% confidence interval [CI] 1.01-4.86). A multivariate linear regression model excluding BMI also showed that AHI was significantly associated with CAC (P = 0.004). However, this association was no longer significant after adjusting for BMI. CONCLUSIONS: In our cross-sectional study, even though both OSA and obesity were positively associated with the presence and extent of CAC, only obesity remained a significant independent contributor after an adjustment for potential cardiovascular risk factors, irrespective of OSA.

Correlation of umbilical cord blood haematopoietic stem and progenitor cell levels with birth weight: implications for a prenatal influence on cancer risk.

We examined the relation with birth weight and umbilical cord blood concentrations of haematopoietic stem and progenitor populations in 288 singleton infants. Across the whole range of birth weight, there was a positive relation between birth weight and CD34+CD38(-) cells, with each 500 g increase in birth weight being associated with a 15.5% higher (95% confidence interval: 1.6-31.3%) cell concentration. CD34+ and CD34+c-kit+ cells had J-shaped relations and CFU-GM cells had a U-shaped relation with birth weight. Among newborns with >or=3000 g birth weights, concentrations of these cells increased with birth weight, while those below 3000 g had higher stem cell concentrations than the reference category of 3000-3499 g. Adjustment for cord blood plasma insulin-like growth factor-1 levels weakened the stem and progenitor cell-birth weight associations. The positive associations between birth weight and stem cell measurements for term newborns with a normal-to-high birth weight support the stem cell burden hypothesis of cancer risk.

A prospective study of age and lifestyle factors in relation to community-acquired pneumonia in US men and women.

BACKGROUND: Information is limited on risk factors for community-acquired pneumonia (CAP) in free-living populations. We examined the associations of age, smoking status, body mass index (BMI), weight change during adulthood, physical activity, and alcohol intake with risk of CAP among men and women. METHODS: The study population included 26,429 men aged 44 to 79 years from the Health Professionals Follow-up Study and 78,062 women aged 27 to 44 years from the Nurses' Health Study II. Information was collected by biennial mailed questionnaires and the main outcome was physician-diagnosed incident pneumonia. RESULTS: There were 290 cases among men (6 years of follow-up) and 305 cases among women (2 years of follow-up). Age, smoking status, BMI, physical activity, and alcohol intake were taken into account in the multivariate logistic regression model. There was a dose-response relation between aging and risk of CAP among men. Compared with never smokers, current smoking was associated with risk of CAP among men (relative risk, 1.46; 95% confidence interval, 1.00-2.14) and women (relative risk, 1.55; 95% confidence interval, 1.15-2.10). In addition, BMI was directly associated with an increased risk of CAP among women. Compared with the participants who maintained their weight during adulthood, the risks were nearly 2-fold higher among men and women who gained 40 lb or more (> or =18 kg). The risk of CAP decreased with increasing physical activity among women. We also found no significant relation between alcohol intake and risk of CAP among men and women. CONCLUSIONS: Smoking and excessive weight gain are risk factors for CAP among men and women, and physical activity was inversely associated with risk of CAP only among women. The incidence of CAP could possibly be decreased by lifestyle factors.

Adiposity and mortality in men.

The relation between measures of adiposity and mortality has been a controversial topic. The authors examined prospectively the relation between several measures of adiposity and risks of overall and cause-specific mortality in 39,756 US men aged 40-75 years. During 10 years of follow-up (1986-1996), 1,972 deaths (747 from cancer, 423 from cardiovascular disease, and 802 from other causes) were documented. An elevated risk of death among the leanest men was partly accounted for by excess mortality during early follow-up and high mortality among those with a history of recent weight loss. After exclusion of men with substantial recent weight loss and deaths occurring during the first 4 years of follow-up, overall and cardiovascular disease mortality among men aged <65 years increased linearly with greater body mass index (BMI) (weight (kg)/height (m)2); multivariate relative risks for overall mortality were 1.0 (referent) for a BMI of <23, 1.21 for a BMI of 23-24.9, 1.19 for a BMI of 25-26.9, 1.39 for a BMI of 27-29.9, and 1.97 for a BMI of >30 (test for trend: p< 0.001). Among men aged > or =65 years, there were no significant relations between BMI and overall, cardiovascular disease, or cancer mortality risk. However, waist circumference strongly predicted risk of death from cardiovascular disease among the older men. These findings indicated that the relation between body fat and mortality was influenced by reverse causation and varied by age.