The association between benzo[a]pyrene-DNA adducts and body mass index, calorie intake and physical activity

Prior work suggests that body size and fat content may influence carcinogen-DNA adduct levels measured in white blood cells. Here we consider energy balance more broadly by assessing the impact of body mass index (BMI), physical activity and calorie intake on the presence of benzo[a]pyrene-DNA (BP-DNA) adducts in white blood cell DNA. Our cross-sectional study employed subjects from a separately conducted intervention trial. Physical activity and food intake data were collected at 12 and 15 months of follow-up, respectively. BP-DNA adducts were measured by high-performance liquid chromatography (HPLC) in white blood cell samples collected at 12 months of follow-up. Complete data on all variables were available from 143 subjects. Logistic regression showed that BMI was inversely associated with the presence of detectable adducts (OR = 0.90, p=0.02), and that hours of moderate-intensity physical activity were positively associated with the presence of detectable adducts (OR = 1.04, p=0.04). These results provide further evidence that body fat content influences carcinogen-DNA adduct levels, probably by altering the distribution of the lipophilic parent compound.     

The damage-associated molecular pattern HMGB1 is released early after clinical hepatic ischemia/reperfusion

Objective and backgroundActivation of sterile inflammation after hepatic ischemia/reperfusion (I/R) culminates in liver injury. The route to liver damage starts with mitochondrial oxidative stress and cell death during early reperfusion. The link between mitochondrial oxidative stress, damage-associate molecular pattern (DAMP) release, and sterile immune signaling is incompletely understood and lacks clinical validation. The aim of the study was to validate this relation in a clinical liver I/R cohort and to limit DAMP release using a mitochondria-targeted antioxidant in I/R-subjected mice.MethodsPlasma levels of the DAMPs high-mobility group box 1 (HMGB1), mitochondrial DNA, and nucleosomes were measured in 39 patients enrolled in an observational study who underwent a major liver resection with (N = 29) or without (N = 13) intraoperative liver ischemia. Circulating cytokine and neutrophil activation markers were also determined. In mice, the mitochondria-targeted antioxidant MitoQ was intravenously infused in an attempt to limit DAMP release, reduce sterile inflammation, and suppress I/R injury.ResultsIn patients, HMGB1 was elevated following liver resection with I/R compared to liver resection without I/R. HMGB1 levels correlated positively with ischemia duration and peak post-operative transaminase (ALT) levels. There were no differences in mitochondrial DNA, nucleosome, or cytokine levels between the two groups. In mice, MitoQ neutralized hepatic oxidative stress and decreased HMGB1 release by ±50%. MitoQ suppressed transaminase release, hepatocellular necrosis, and cytokine production. Reconstituting disulfide HMGB1 during reperfusion reversed these protective effects.ConclusionHMGB1 seems the most pertinent DAMP in clinical hepatic I/R injury. Neutralizing mitochondrial oxidative stress may limit DAMP release after hepatic I/R and reduce liver damage.     

Long-term trends in body mass index of children in Jena, Eastern Germany

The body mass index (BMI) is widely used as an indicator of nutritional status of individuals and groups, changes in this measure reflecting changes in living conditions. The purpose of this paper is to present long-term BMI trends of schoolchildren from Jena/Eastern Germany over 125 years. The analysis is based on 10 anthropological investigations carried out between 1880 and 2005/2006 and belongs to the longest running, continuous investigation of schoolchildren in a single community worldwide. The average BMI of the 7- to 14-year-old probands generally increases between the first investigation in 1880 and the last study in 2005/2006 by 1.8 kg/m(2) in boys and by 2.1 kg/m(2) in girls. However, this long-term increase of the BMI does not occur continuously. The trend was interrupted for example by declining average BMI values between 1932 and 1944. In contrast, the time after German reunification is characterised by a marked increase in this measure. The changes in BMI of Jena schoolchildren are also analysed in relation to energy intake in different years. There is an association between changes in energy intake and changes in BMI, which weakens after 1985. This indicates that the recent dramatic increase in the prevalence of overweight and obesity is not only due to an increased energy intake but also reflects a more inactive lifestyle of children and adolescents. The continuing change in the BMI pattern of Jena children and adolescents is discussed in regard to programmes of prevention of overweight and obesity.     

Birth weight and physical stature in St. Petersburg: Living standards of women in Russia, 1980–2005

We analyze data on the height and weight of mothers and newborn babies between 1980 and 2005 in St. Petersburg, Russia. We find that women's living standards, as measured by their height, improved steadily from the end of World War II through those born in 1972, hence reached adulthood in 1990. Thereafter, heights declined. Evidence on both the length and weight of babies corroborates this pattern. Their values trace a "U" shaped curve with troughs near the mid-1990s. Thus, the anthropometric results on newborn as well as for their mother point to the strains and challenges to living standards experienced during the restructuring of the post-Soviet economy. This is a general result that has become a recurring pattern: economic transitions are almost always accompanied by biological strains.     

Activity, inactivity, and screen time in relation to weight and fatness over adolescence in girls

Objective: The impact of activity and inactivity on relative weight and fatness change are best evaluated longitudinally. We examined the longitudinal relationship of physical activity, inactivity, and screen time with relative weight status and percentage body fat (%BF) and explored how it differed by parental overweight status. Research Methods and Procedures: Non‐obese pre‐menarcheal girls (173), 8 to 12 years old, were followed until 4 years post‐menarche. %BF, BMI z‐score, and time spent sleeping, sitting, standing, walking, and in vigorous activity were assessed annually. We developed a physical activity index to reflect time and intensity of activity. Inactivity was defined as the sum of time spent sleeping, sitting, and standing. Screen time was defined as time spent viewing television, videotapes, or playing video games. Parental overweight was defined as at least one parent with BMI > 25. Results: In separate linear mixed effects models, activity, inactivity, and screen time were unrelated to BMI z‐score longitudinally, with and without accounting for parental overweight. After controlling for parental overweight, activity was inversely related (p < 0.001), and inactivity was directly related (p < 0.035) to increased %BF longitudinally. Screen time was unrelated to %BF change. With stratification for parental overweight, effects of activity and inactivity on %BF were observed only among girls with at least one overweight parent. Discussion: In this cohort of initially non‐overweight girls, activity and inactivity were related to accrual of BF over adolescence, particularly among children with at least one overweight parent. These results suggest that girls with a family history of overweight represent a target population of high priority for interventions around physical activity and inactivity.     

BMI may overestimate the prevalence of obesity among women of lower socioeconomic status

Objective: Our objective was to examine gender differences in height and weight associated with socioeconomic status (SES) and the consequent effect on body mass index in a multiethnic society. Research Methods and Procedures: A cross‐sectional study, the First Israeli National Health and Nutrition Survey, was performed on a representative population sample of 3246 adults 25 to 64 years of age, between the years 1999 to 2001. Height and weight were measured, and BMI and other weight‐height indices were calculated. SES was assessed by income and education. Results: Age‐adjusted height was significantly lower at lower levels of SES among both women and men (p < 0.001). As opposed to men, women of lower SES were heavier than those of higher SES, and the mean age‐adjusted weight was 4.6 kg higher among those of lower SES (p < 0.001). Thus, using the standard index of BMI, the prevalence of obesity was significantly higher among shorter women. Discussion: In this group of Israeli adults, the unfavorable effect of low SES on BMI was evident among women, partly due to their decreased height combined with increased weight common in this socioeconomic sector. Since BMI is only partly independent of height, it may overestimate the prevalence of obesity among women of lower SES. Alternative measures for classifying obesity in the lower SES groups that put less emphasis on height may be considered and studied.     

Overall and central obesity and risk of type 2 diabetes in U.S. black women

Objective: Obesity has risen to epidemic proportions in the United States, leading to an emerging epidemic of type 2 diabetes. African‐American women are disproportionately affected by both conditions. While an association of overall obesity with increasing risk of diabetes has been documented in black women, the effect of fat distribution, specifically abdominal obesity, has not been studied. We examined the association of BMI, abdominal obesity, and weight gain with risk of type 2 diabetes. Research Methods and Procedures: During eight years of follow‐up of 49,766 women from the Black Women's Health Study, 2472 incident cases of diabetes occurred. Cox proportional hazard models were used to estimate incidence rate ratios (IRRs), with control for age, physical activity, family history of diabetes, cigarette smoking, years of education, and time period of data collection. Results: Sixty‐one percent of participants had a BMI ≥25 kg/m² (WHO definition of overweight). Compared with a BMI of <23 kg/m², the IRR for a BMI of >45 kg/m² was 23 (95% confidence interval, 17.0 to 31.0). The IRR for the highest quintile of waist‐to‐hip ratio relative to the lowest was 2.3 (95% confidence interval, 2.0 to 2.7) after control for BMI. Furthermore, at every level of BMI, an increased risk was observed for high waist‐to‐hip ratio relative to low. Discussion: Central obesity, as well as overall obesity, is a strong risk factor for diabetes in African‐American women. Efforts to reduce the prevalence of obesity in African‐American women are of paramount importance.     

Does Childhood Sexual Abuse Predict Young Adult's BMI? A Birth Cohort Study

Objective: The objective was to identify the extent to which childhood sexual abuse (CSA) is associated with BMI and overweight status in young adulthood and to examine whether any associations differ by gender. Research Methods and Procedures: The Mater‐University of Queensland Study of Pregnancy is a prospective birth cohort from a population‐based sample involving 7223 singletons whose mothers were enrolled in the 1980s at the first antenatal visit. The present cohort consisted of a subgroup of 2461 young adults who had both self‐reported CSA data and measured BMI at 21 years. Results: Of 1273 men, 10.5% reported non‐penetrative and 7.5% reported penetrative CSA before age 16 years. Of 1305 women, 20.6% reported non‐penetrative and 7.9% reported penetrative CSA by age 16 years. We found young women's BMI and the prevalence of overweight at age 21 were greater in those who experienced penetrative CSA. This association was robust to adjustment for a variety of potential confounders. However, there was no association between non‐penetrative CSA and BMI in women and no association between either category of CSA and BMI in men. There was statistical evidence for a gender difference in the association of CSA with mean BMI at age 21 (p value for statistical interaction <0.01 in all models). Discussion: These findings suggest that among women, penetrative CSA is associated with greater BMI and increased odds of being overweight in later life, whereas in men, this association does not hold. This gender difference may reflect differences between women and men in the relationship between psychological trauma and body image or may be a chance subgroup finding.     

Cardiorespiratory fitness and sedentary activities are associated with adiposity in adolescents

Objective: To determine whether physical activity, sedentary activities, and/or cardiorespiratory fitness are related to waist circumference in adolescents, as previously reported in adults. Research Methods and Procedures: The study subjects were a representative sample of Spanish adolescents (N = 2859; 1357 boys, 1502 girls; age, 13 to 18.5 years), all of whom were involved in the AVENA (Food and Assessment of the Nutritional Status of Adolescents) study. BMI, waist circumference, pubertal maturation status, and cardiorespiratory fitness were measured in all. Leisure‐time physical activity, sedentary activities, active commuting to school, and socioeconomic status were assessed by self‐reported questionnaires. Results: No relationship was found between leisure‐time physical activity and BMI or waist circumference. In contrast, and in both boys and girls and after adjustment for confounding variables, cardiorespiratory fitness was found to be inversely associated with waist circumference and BMI, independent of sedentary activities or physical activity (p ≤ 0.001). The maximum oxygen consumption explained 13% of the variance in waist circumference in boys and 16% in girls. Sedentary activities were independently and directly related to waist circumference in both boys and girls (p ≤ 0.05) and to BMI in boys (p ≤ 0.05). Sedentary activities explained 10% of the variance in waist circumference in boys and 18% in girls. The BMI‐adjusted waist circumference was inversely correlated with cardiorespiratory fitness in overweight‐obese boys (p ≤ 0.05) and showed a trend toward significance in girls (p ≤ 0.1). Discussion: Both moderate to high levels of cardiorespiratory fitness and sedentary activities, but not physical activity, are associated with lower abdominal adiposity, as measured by waist circumference.