Genetic and social influences on starting to smoke: a study of Dutch adolescent twins and their parents

In a study of 1600 Dutch adolescent twin pairs we found that 59% of the inter‐individual variation in smoking behaviour could be attributed to shared environmental influences and 31% to genetic factors. The magnitude of the genetic and environmental effects did not differ between boys and girls. However, environmental effects shared by male twins and environmental effects shared by female twins were imperfectly correlated in twins from opposite‐sex pairs, indicating that different environmental factors influence smoking in adolescent boys and girls. In the parents of these twins, the correlation between husband and wife for‘currently smoking’(r = 0.43) was larger than for‘ever smoked’(r = 0.18). There was no evidence that smoking of parents (at present or in the past) encouraged smoking in their offspring. Resemblance between parents and offspring was significant but rather low and could be accounted for completely by their genetic relatedness. Moreover, the association between‘currently smoking’in the parents and smoking behaviour in their children was not larger than the association between‘ever smoking’in parents and smoking in their children. Copyright © 1994, Wiley Blackwell. All rights reserve

Associations of physical activity with body weight and fat in men and women

OBJECTIVE: Increasing physical activity is strongly advocated as a key public health strategy for weight gain prevention. We investigated associations of leisure-time physical activity (LTPA) and occupational/domestic physical activity with body mass index (BMI) and a skinfold-derived index of body fat (sum of six skinfolds), among normal-weight and overweight men and women.DESIGN: Analyses of cross-sectional self-report and measured anthropometric data.SUBJECTS: A total of 1302 men and women, aged 18-78 y, who were part of a randomly selected sample and who agreed to participate in a physical health assessment.MEASUREMENTS: Self-report measures of physical activity, measured height and weight, and a skinfold-derived index of body fatness.RESULTS: Higher levels of LTPA were positively associated with the likelihood of being in the normal BMI and lower body fat range for women, but few or no associations were found for men. No associations were found between measures of occupational/domestic activity and BMI or body fat for men or women.CONCLUSION: By using a skinfold sum as a more direct measure of adiposity, this study extends and confirms the previous research that has shown an association between BMI and LTPA. Our results suggest gender differences in the relationship of leisure-time physical activity with body fatness. These findings, in conjunction with a better understanding of the causes of such differences, will have important public health implications for the development and targeting of weight gain prevention strategies.<br /

Odontostomatologic management of patients receiving oral anticoagulant therapy: a retrospective multicentric study

Introduction: Today, we frequently find patients taking oral anticoagulant therapy (OAT), a prophylaxis against the occurrence of thromboembolic events. An oral surgeon needs to know how to better manage such patients, in order to avoid hemorrhagic and thromboembolic complications. Materials and methods: A group of 193 patients (119 men aged between 46 and 82 and 74 women aged between 54 and 76) undergoing OAT for more than 5 years were managed with a standardized management protocol and a 2-months follow-up. The aim of the present study was to apply a protocol, which could provide a safe intra- and postoperative management of patients on OAT. Results: Among the 193 patients, only 2 had postoperative complications. Conclusions: We think that the protocol used in the present study can be used for complete safety in the treatment of this type of patients. Keywords: Oral Anticoagulant Therapy (OAT), Tranexamic Acid, Oral Surger

Summer effects on body mass index (BMI) gain and growth patterns of American Indian children from kindergarten to first grade: a prospective study

<p>Abstract</p> <p>Background</p> <p>Overweight and obesity are highly prevalent among American Indian children, especially those living on reservations. There is little scientific evidence about the effects of summer vacation on obesity development in children. The purpose of this study was to investigate the effects of summer vacation between kindergarten and first grade on growth in height, weight, and body mass index (BMI) for a sample of American Indian children.</p> <p>Methods</p> <p>Children had their height and weight measured in four rounds of data collection (yielded three intervals: kindergarten, summer vacation, and first grade) as part of a school-based obesity prevention trial (Bright Start) in a Northern Plains Indian Reservation. Demographic variables were collected at baseline from parent surveys. Growth velocities (Z-score units/year) for BMI, weight, and height were estimated and compared for each interval using generalized linear mixed models.</p> <p>Results</p> <p>The children were taller and heavier than median of same age counterparts. Height Z-scores were positively associated with increasing weight status category. The mean weight velocity during summer was significantly less than during the school year. More rapid growth velocity in height during summer than during school year was observed. Obese children gained less adjusted-BMI in the first grade after gaining more than their counterparts during the previous two intervals. No statistically significant interval effects were found for height and BMI velocities.</p> <p>Conclusions</p> <p>There was no indication of a significant summer effect on children's BMI. Rather than seasonal or school-related patterns, the predominant pattern indicated by weight-Z and BMI-Z velocities might be related to age or maturation.</p> <p>Trial registration</p> <p>Bright Start: Obesity Prevention in American Indian Children Clinical Trial Govt ID# <a href="http://www.clinicaltrials.gov/ct2/show/NCT00123032">NCT00123032</a></p

An investigation of the effects of lipid-lowering medications: genome-wide linkage analysis of lipids in the HyperGEN study

BACKGROUND: Use of anti-hyperlipidemic medications compromises genetic analysis because of altered lipid profiles. We propose an empirical method to adjust lipid levels for medication effects so that the adjusted lipid values substitute the unmedicated lipid values in the genetic analysis. RESULTS: Published clinical trials were reviewed for HMG-CoA reductase inhibitors and fibric acid derivatives as mono-drug therapy. HMG-CoA reductase inhibitors showed similar effects in African Americans (AA) and non-African Americans (non-AA) for lowering total cholesterol (TC, -50.7 mg/dl), LDL cholesterol (LDL-C, -48.1 mg/dl), and triglycerides (TG, -19.7 mg/dl). Their effect on increasing HDL cholesterol (HDL-C) in AA (+0.4 mg/dl) was lower than in Non-AA (+2.3 mg/dl). The effects of fibric acid derivatives were estimated as -46.1 mg/dl for TC, -40.1 mg/dl for LDL-C, and +5.9 mg/dl for HDL-C in non-AA. The corresponding effects in AA were less extreme (-20.1 mg/dl, -11.4 mg/dl, and +3.1 mg/dl). Similar effect for TG (59.0 mg/dl) was shown in AA and non-AA. The above estimated effects were applied to a multipoint variance components linkage analysis on the lipid levels in 2,403 Whites and 2,214 AA in the HyperGEN study. The familial effects did vary depending on whether the lipids were adjusted for medication use. For example, the heritabilities increased after medication adjustment for TC and LDL-C, but did not change significantly for HDL-C and TG. CONCLUSION: Ethnicity-specific medication adjustments using our empirical method can be employed in epidemiological and genetic analysis of lipids.National Heart, Lung, and Blood Institute (HL554471, HL54472, HL54473, HL54495, HL54496, HL54497, HL54509, HL54515

Meta-analysis on the effect of the N363S polymorphism of the glucocorticoid receptor gene (GRL) on human obesity

BACKGROUND: Since both excess glucocorticoid secretion and central obesity are clinical features of some obese patients, it is worthwhile to study a possible association of glucocorticoid receptor gene (GRL) variants with obesity. Previous studies have linked the N363S variant of the GRL gene to increased glucocorticoid effects such as higher body fat, a lower lean-body mass and a larger insulin response to dexamethasone. However, contradictory findings have been also reported about the association between this variant and obesity phenotypes. Individual studies may lack statistical power which may result in disparate results. This limitation can be overcome using meta-analytic techniques. METHODS: We conducted a meta-analysis to assess the association between the N363S polymorphism of the GRL gene and obesity risk. In addition to published research, we included also our own unpublished data -three novel case-control studies- in the meta-analysis The new case-control studies were conducted in German and Spanish children, adolescents and adults (total number of subjects: 1,117). Genotype was assessed by PCR-RFLP (Tsp509I). The final formal meta-analysis included a total number of 5,909 individuals. RESULTS: The meta-analysis revealed a higher body mass index (BMI) with an overall estimation of +0.18 kg/m(2 )(95% CI: +0.004 to +0.35) for homo-/heterozygous carriers of the 363S allele of the GRL gene in comparison to non-carriers. Moreover, differences in pooled BMI were statistically significant and positive when considering one-group studies from the literature in which participants had a BMI below 27 kg/m(2 )(+ 0.41 kg/m(2 )[95% CI +0.17 to +0.66]), but the differences in BMI were negative when only our novel data from younger (aged under 45) and normal weight subjects were pooled together (-0.50 kg/m(2 )[95% CI -0.84 to -0.17]). The overall risk for obesity for homo-/heterozygous carriers of the 363S allele was not statistically significant in the meta-analysis (pooled OR = 1.02; 95% CI: 0.56–1.87). CONCLUSION: Although certain genotypic effects could be population-specific, we conclude that there is no compelling evidence that the N363S polymorphism of the GRL gene is associated with either average BMI or obesity risk

Exercise and the Prevention of Oesophageal Cancer (EPOC) study protocol: a randomized controlled trial of exercise versus stretching in males with Barrett's oesophagus

<p>Abstract</p> <p>Background</p> <p>Chronic gastro-oesophageal reflux disease and excessive body fat are considered principal causes of Barrett's oesophagus (a metaplastic change in the cells lining the oesophagus) and its neoplastic progression, oesophageal adenocarcinoma. Metabolic disturbances including altered levels of obesity-related cytokines, chronic inflammation and insulin resistance have also been associated with oesophageal cancer development, especially in males. Physical activity may have the potential to abrogate metabolic disturbances in males with Barrett's oesophagus and elicit beneficial reductions in body fat and gastro-oesophageal reflux symptoms. Thus, exercise may be an effective intervention in reducing oesophageal adenocarcinoma risk. However, to date this hypothesis remains untested.</p> <p>The 'Exercise and the Prevention of Oesophageal Cancer Study' will determine whether 24 weeks of exercise training will lead to alterations in risk factors or biomarkers for oesophageal adenocarcinoma in males with Barrett's oesophagus. Our primary outcomes are serum concentrations of leptin, adiponectin, tumour necrosis factor-alpha, C-reactive protein and interleukin-6 as well as insulin resistance. Body composition, gastro-oesophageal reflux disease symptoms, cardiovascular fitness and muscular strength will also be assessed as secondary outcomes.</p> <p>Methods/Design</p> <p>A randomized controlled trial of 80 overweight or obese, inactive males with Barrett's oesophagus will be conducted in Brisbane, Australia. Participants will be randomized to an intervention arm (60 minutes of moderate-intensity aerobic and resistance training, five days per week) or a control arm (45 minutes of stretching, five days per week) for 24 weeks. Primary and secondary endpoints will be measured at baseline (week 0), midpoint (week 12) and at the end of the intervention (week 24).</p> <p>Discussion</p> <p>Due to the increasing incidence and very high mortality associated with oesophageal adenocarcinoma, interventions effective in preventing the progression of Barrett's oesophagus are urgently needed. We propose that exercise may be successful in reducing oesophageal adenocarcinoma risk. This primary prevention trial will also provide information on whether the protective association between physical activity and cancer is causal.</p> <p>Trial Registration</p> <p>ACTRN12609000401257</p