Can lifestyle factors explain why body mass index and waist-to-hip ratio increase with increasing tobacco consumption? The Inter99 study

Effect of a lifestyle intervention to prevent weight gain at initiation of insulin pump therapy in type 2 diabetes: a randomized, controlled, multicentre trial

Insulin pump therapy improves glycaemic control in individuals with type 2 diabetes. However, it may be associated with weight gain.

AIM

To test the effectiveness of a six-month dietary and physical activity intervention, compared to usual care, on weight gain prevention after initiation of insulin pump.

METHODS

Multicentre randomized, controlled trial of 54 individuals. Primary endpoint was between group difference in weight gain at six-months.

RESULTS

Weight gain after 6 months of insulin pump treatment did not differ between groups: mean 3.2 (3.9) kg in the control group and 3.9 (3.8) kg in the intervention group, (p=0.56). HbA1c improved without difference between groups. Post-hoc multivariate analysis of all participants found that weight gain was independently associated with younger age, active smoking, and the magnitude of HbA1c reduction. A 1% decrease in HbA1c was associated with an increase of 0.94kg [95% Confidence Interval 0.47; 1.41], p<0.001.

CONCLUSIONS

Treatment intensification by insulin pump therapy in patients with type 2 diabetes is effective to improve glycaemic control. A gain of about 1 kg per 1% drop in HbA1c can be expected after insulin treatment intensification. This weight gain was not prevented by a home-base, individualized, 6-months lifestyle intervention program.

Nutritional counseling frequency and baseline food pattern predict implementation of a high-protein and high-polyunsaturated fatty acid dietary pattern: 1-year results of the randomized NutriAct trial

BACKGROUND & AIMS

NutriAct is a 36-month randomized controlled multi-center trial designed to analyze the effects of a food pattern focusing on a high-protein and high-unsaturated fatty acids (UFA) intake on healthy aging. We aimed to determine factors associated with a successful modulation of dietary pattern after 12 months in elderly participants.

METHODS

502 participants were randomized into either usual care control group including dietary recommendations of the German Nutrition Society (DGE) or an intervention group, which used supplementation of rapeseed oil and specifically designed foods as well as repetitive advices to implement a food pattern based on high intake of predominantly plant proteins, UFA and fiber (NutriAct pattern). Food intake was repeatedly assessed by 3-day food records at months 0, 3, 6 and 12. Linear regression models were used to investigate determinants of basal food intake and modulation of dietary pattern during the intervention.

RESULTS

Food records of 242 intervention and 246 control participants (median age 66 y, 37% males) were available at baseline and were included. At baseline, high BMI was related to higher protein and saturated fatty acids and lower fiber intake. The intervention resulted in higher intake of protein, mono- and polyunsaturated fatty acids (MUFA and PUFA) and fiber, and lower carbohydrate and saturated fatty acid consumption (all p < 0.001). While individuals who were already at baseline closer to the NutriAct pattern also achieved a diet closer to the proposed pattern at month 12, the strongest absolute changes (%E) of dietary behavior were seen in those with dietary patterns further away from the proposed pattern at baseline. Attendance to nutritional sessions was crucial to change MUFA, PUFA, fiber and carbohydrate intake.

CONCLUSIONS

A successful modification of dietary pattern was achieved by the performed intervention within 12 months. Baseline dietary habits and attendance to nutritional sessions were substantial determinants predicting changes in dietary pattern.

CLINICAL TRIAL REGISTRATION

The trial was registered at German Clinical Trials Register (drks.de) as DRKS00010049.

Associations of tobacco smoking with body mass distribution; a population-based study of 65,875 men and women in midlife

BACKGROUND

Studies indicate an effect of smoking toward abdominal obesity, but few assess hip and waist circumferences (HC and WC) independently. The present study aimed to assess the associations of smoking status and volume smoked with HC and WC and their ratio in a population with low prevalence of obesity together with high prevalence of smoking.

METHODS

We used cross-sectional survey data from 11 of a total 19 Norwegian counties examined in 1997-99 including 65,875 men and women aged 39-44 years. Analysis of associations were adjusted for confounding by socioeconomic position, health indicators, and additionally for BMI.

RESULTS

Compared with never-smokers, when adjusting for confounders and in addition for BMI, mean HC remained lower while mean WC and waist-hip-ratio (WHR) were higher in current smokers. The finding of a lower HC and higher WHR level among smokers was consistent by sex and in strata by levels of education and physical activity, while the finding of higher WC by smoking was less consistent. Among current smokers, BMI-adjusted mean HC decreased whereas WC and WHR increased by volume smoked. Compared with current smokers, former smokers had higher BMI-adjusted HC, lower WHR and among women WC was lower.

CONCLUSIONS

The main finding in this study was the consistent negative associations of smoking with HC. In line with the hypothesis that lower percentage gluteofemoral fat is linked with higher cardiovascular risk, our results suggest that smoking impacts cardiovascular risk through mechanisms that reduce the capacity of fat storage in the lower body region.

Association of current and former smoking with body mass index: A study of smoking discordant twin pairs from 21 twin cohorts

Background

Smokers tend to weigh less than never smokers, while successful quitting leads to an increase in body weight. Because smokers and non-smokers may differ in genetic and environmental family background, we analysed data from twin pairs in which the co-twins differed by their smoking behaviour to evaluate if the association between smoking and body mass index (BMI) remains after controlling for family background.

Methods and findings

The international CODATwins database includes information on smoking and BMI measured between 1960 and 2012 from 156,593 twin individuals 18–69 years of age. Individual-based data (230,378 measurements) and data of smoking discordant twin pairs (altogether 30,014 pairwise measurements, 36% from monozygotic [MZ] pairs) were analysed with linear fixed-effects regression models by 10-year periods. In MZ pairs, the smoking co-twin had, on average, 0.57 kg/m² lower BMI in men (95% confidence interval (CI): 0.49, 0.70) and 0.65 kg/m² lower BMI in women (95% CI: 0.52, 0.79) than the never smoking co-twin. Former smokers had 0.70 kg/m² higher BMI among men (95% CI: 0.63, 0.78) and 0.62 kg/m² higher BMI among women (95% CI: 0.51, 0.73) than their currently smoking MZ co-twins. Little difference in BMI was observed when comparing former smoking co-twins with their never smoking MZ co-twins (0.13 kg/m², 95% CI 0.04, 0.23 among men; -0.04 kg/m², 95% CI -0.16, 0.09 among women). The associations were similar within dizygotic pairs and when analysing twins as individuals. The observed series of cross-sectional associations were independent of sex, age, and measurement decade.

Conclusions

Smoking is associated with lower BMI and smoking cessation with higher BMI. However, the net effect of smoking and subsequent cessation on weight development appears to be minimal, i.e. never more than an average of 0.7 kg/m².

Smoking status and abdominal obesity among normal- and overweight/obese adults: Population-based FINRISK study

Several studies have reported direct associations of smoking with body mass index (BMI) and abdominal obesity. However, the interplay between them is poorly understood. Our first aim was to investigate the interaction between smoking status and BMI on abdominal obesity (waist circumference, WC). Our second aim was to examine how the association of smoking status with WC varies among normal and overweight/obese men and women. We examined 5833 participants from the National FINRISK 2007 Study. The interactions between smoking and BMI on WC were analyzed. Participants were categorized into eight groups according to BMI (normal weight vs. overweight/obese) and smoking status (never smoker, ex-smoker, occasional/light/moderate daily smoker, heavy daily smoker). The associations between each BMI/smoking status -group and WC were analyzed by multiple regressions, the normal-weight never smokers as the reference group. The smoking status by BMI-interaction on WC was significant for women, but not for men. Among the overweight/obese women, ex-smokers (β = 2.73; 1.99, 3.46) and heavy daily smokers (β = 4.90; 3.35, 6.44) had the highest estimates for WC when adjusted for age, BMI, alcohol consumption and physical activity. In comparison to never smoking overweight/obese women, the β-coefficients of ex-smokers and heavy daily smokers were significantly higher. Among men and normal weight women the β -coefficients did not significantly differ by smoking status. An interaction between smoking status and BMI on abdominal obesity was observed in women: overweight/obese heavy daily smokers were particularly vulnerable for abdominal obesity. This risk group should be targeted for cardiovascular disease prevention.

High tobacco consumption lowers body weight: a Mendelian randomization study of the Copenhagen General Population Study

BACKGROUND

Conflicting evidence has been found regarding the association between high tobacco consumption and body weight among smokers. We tested the hypothesis that high tobacco consumption is causally associated with low body weight.

METHODS

We conducted a Mendelian randomization study with a genetic variant in CHRNA3 (rs1051730) as proxy for high tobacco consumption. The cohort consisted of 80,342 participants from the Copenhagen General Population Study, with details on body weight, smoking habits and CHRNA3 genotype, including 15,220 current smokers.

RESULTS

In observational analyses, high tobacco consumption was associated with high body weight, body mass index, waist circumference, hip circumference and waist-hip ratio. In multivariable adjusted models a 1-cigarette/day higher tobacco consumption was associated with 0.05 kg (95% confidence interval 0.02; 0.08) higher body weight, 0.02 kg/m(2) (0.01; 0.02) higher body mass index, 0.10 cm (0.07; 0.12) higher waist circumference and 0.02 cm (0.001; 0.03) higher hip circumference. In contrast, the per-allele increase inCHRNA3 rs1051730 associated with high tobacco consumption was associated with 0.59 kg (0.96; 0.22) lower body weight, 0.23 kg/m(2) (0.33; 0.13) lower body mass index, 0.32 cm (0.74; 0.003) lower waist circumference and 0.45 cm (0.66; 0.24) lower hip circumference. No association was found between tobacco consumption and waist-hip ratio in genetic analysis, or among CHRNA3 genotype and any of the outcome variables in former or never smokers.

CONCLUSIONS

High tobacco consumption causes lower body weight among current smokers. However, smoking does not seem to affect body shape or fat distribution causally. The lack of association between CHRNA3 genotype and body weight among former smokers and never smokers favours smoking as the causal factor for the observed associations.

Clustering of lifestyle factors in Spanish university students: the relationship between smoking, alcohol consumption, physical activity and diet quality

OBJECTIVE

To ascertain the prevalence of and association between main lifestyle factors (diet, physical activity, alcohol consumption and smoking) in students from the Balearic Islands University.

DESIGN

A cross-sectional, descriptive study. A questionnaire including questions on lifestyle, dietary habits and physical activity habits was administered to the students. Four different diet quality scores were calculated (Diet Diversity Score, Mediterranean Diet Score, Dietary Guidelines Score and Global Dietary Guidelines Score).

SETTING

A sample of students from the Balearic Islands University.

SUBJECTS

Nine hundred and eighty-seven students (45·5 % males; mean age 21·5 (sd 3·3) years).

RESULTS

The dietary pattern of the student population was characterized by a low consumption of cereals and tubers, fruits, vegetables, olive oil, legumes and nuts, and a high consumption of processed meat, sweets, snacks, soft drinks and pastries. Linear, positive and statistically significant correlations were found between the number of meals consumed daily and all of the diet quality scores determined. Determinants of diet quality, both in the univariate and multivariate analyses, were physical activity practice, sex, age and number of meals consumed daily.

CONCLUSIONS

Risk factors such as smoking, diet and physical inactivity had a tendency of clustering among Spanish university students. Overall diet quality was low, due to important departures from dietary recommendations and loss of the traditional Mediterranean dietary pattern. Nutritional education campaigns that include promotion of physical activity practice are needed to improve the overall health status of this population.

Health behaviors among short- and long- term ex-smokers: results from the Thai National Health Examination Survey IV, 2009

BACKGROUND

Although numerous studies have shown the health behaviors of ex-smokers to be better than those in regular smokers, the differences in health behaviors among ex-smokers at varying durations of cessation have not been investigated. This study aims to examine the relationship between different durations of smoking cessation and health behaviors.

METHODS

Data on dietary intake, alcohol consumption, physical activity, and smoking behavior from the Thai National Health Examination Survey IV for subjects aged 15-98 years (n=19 371) were included in the analysis. Trends between health behaviors among regular smokers, ex-smokers with different durations of smoking (<1 year, 1-10 years, >10 years), and never smokers were tested. Logistic regression models adjusted for sex, age, and economic status were used.

RESULTS

The prevalences of regular smoking, ex-smoking, and never smoking were 22.3%, 12% , and 65.7%, respectively. A trend was found for consumption of fruit, beans and meats, dairy and soy milk, whole-grain products, nutritional supplements, and eating habits. Average daily alcohol consumption (g) was lowest among ex-smokers who had quit for>10 years ex-smokers (16.4) followed by 1-10 years ex-smokers (27.2), and <1 year ex-smokers (33.7).

CONCLUSION

A longer duration of smoking cessation correlated with better health behaviors.