An exploration of socioeconomic variation in lifestyle factors and adiposity in the Ontario Food Survey through structural equation modeling

How socioeconomic status affects weight status through health-related lifestyles: a latent class analysis

AIMS

Obesity levels have increased worldwide with serious public health concerns. However, weight status is related to socioeconomic status (SES), which may also influence health-related lifestyles. Here, we study the association between SES and obesity mediated by diet and physical activity.

METHODS AND RESULTS

Using cross-sectional data from 2006, 2011, 2014, and 2017 Spanish health surveys (the final sample consisted of 61 768 adults aged between 18 and 64 years), we conducted a latent class analysis to estimate health-related lifestyle clusters (based on dietary patterns and physical activity) and mediation analyses to evaluate the association of SES and obesity through the clustering of health-related lifestyles. In both men and women, SES was inversely related to obesity (P < 0.001) and positively related to healthier lifestyle classes (P < 0.001). Obesity was inversely related to healthier lifestyle classes (P < 0.001). A small-although significant-proportion mediated by the clustering of lifestyles was found as follows: 4.9%, 95% CI (6.6%, 3.2%) in men and 2.3%, 95% CI (3.4%, 1.3%) in women for educational attainment, 5.3%, 95% CI (7.2%, 3.6%) in men and 2.0%, 95% CI (2.9%, 1.1%) in women for occupational social class, and 4.9%, 95% CI (6.5%, 3.1%) and 1.9%, 95% CI (2.9%, 1.1%) combining the above two SES indicators.

CONCLUSIONS

SES is related to obesity through clustering health-related lifestyles, with greater emphasis on men. However, the complex relationship between SES and weight status also suggests other indicators that contribute to the social gradient of obesity.

Diet and physical activity as possible mediators of the association between educational attainment and body mass index gain among Australian adults

OBJECTIVES

To quantify the mediating role of leisure time physical activity (LTPA) and five dietary behaviours on educational differences in 13-year body mass index (BMI) gain across adulthood.

METHODS

Participants from the Melbourne Collaborative Cohort Study (4791 women; 3103 men) who maintained or gained BMI over 1990-1994 to 2003-2007 and met our inclusion criteria were selected. Education, potential mediators and confounders (age, alcohol, and smoking) were measured at baseline. We conducted sex-specific multiple mediation analyses using MacKinnon's product of coefficients method.

RESULTS

A higher educational attainment was associated with a 0.27 kg m^-2 (95% CI 0.14, 0.39) lesser 13-year BMI gain among women only. We observed significant indirect effects of educational attainment on 13-year BMI gain through LTPA and nutrient-rich foods (each associated with a higher educational attainment and lesser 13-year BMI gain) and diet soft drink (associated with a lower educational attainment and greater 13-year BMI gain), which mediated 10, 15 and 20% of this relationship, respectively (45% in total).

CONCLUSIONS

Nutrient-rich foods, LTPA and diet soft drink may represent effective public health targets to reduce inequities in excess weight across adulthood.

Persistent financial hardship, 11-year weight gain, and health behaviors in the Whitehall II study

OBJECTIVE

To ascertain prospectively gender-specific associations between types and amounts of financial hardship and weight gain, and investigate potential behavioral mechanisms.

METHODS

Prospective study of 3701 adult British civil servants with repeated measures of difficulty paying bills or insufficient money to afford adequate for food/clothing (1985-1988; 1989-1990; 1991-1993; 1997-1999), and weight (1985-1988; 1997-1999).

RESULTS

Persistent hardships were associated with adjusted mean weight change in women over 10.9 years, but no consistent pattern was seen in men. During follow-up, 46% of women gained ≥5 kg. Women reporting persistent insufficient money for food/clothing had a significantly greater odds of gaining ≥5 kg (1.42 [1.05, 1.92]) compared to no hardship history, which remained after socioeconomic status (SES) adjustment (1.45 [1.05, 2.01]). The association between persistent difficulty paying bills and odds of excess weight gain was also significant (1.42 [1.03, 1.97]) but attenuated after considering SES (1.39 [0.98, 1.97]). Four health behaviors as single measures or change variables did not attenuate associations.

CONCLUSIONS

Results suggested strategies to tackle obesity must address employed women's everyday financial troubles which may influence weight through more biological pathways than classical correlates of economic disadvantage and weight.

Explaining educational disparities in adiposity: the role of neighborhood environments

OBJECTIVE

To examine the extent to which characteristics of the neighborhood built environment explain the association between adiposity and educational qualifications in Australian women.

METHODS

A community sample of 1,819 women (aged 18-66) from the Melbourne SESAW study provided information regarding their body mass index (BMI) and level of education. Objective measures of participants' residential neighborhood built environments were obtained using a Geographic Information System.

RESULTS

Compared with women with a high school degree or above, women who did not complete high school had higher average BMI, which was partially explained by lower density of sports facilities and living less proximally to the coastline and to supermarkets. In a multiple mediator model, which explained 16.6% of the educational disparity in BMI, the number of sports facilities and presence of the coastline within 2 km of participants' homes were significant mediators of the observed socioeconomic disparity in BMI.

CONCLUSIONS

The residential neighborhood environment may help to explain socioeconomic patterning of overweight and obesity in Australian women. These results provide further support for considering the built environment in obesity prevention initiatives, suggesting a potential role in decreasing social inequalities in obesity.

FRAX provides robust fracture prediction regardless of socioeconomic status

We investigated the fracture risk assessment tool (FRAX) Canada calibration and discrimination according to income quintile in 51,327 Canadian women, with and without a competing mortality framework. Our data show that, under a competing mortality framework, FRAX provides robust fracture prediction and calibration regardless of socioeconomic status (SES).

INTRODUCTION

FRAX® predicts 10-year fracture risk. Social factors may independently affect fracture risk. We investigated FRAX calibration and discrimination according to SES.

METHODS

Women aged ≥50 years with baseline femoral neck bone mineral density (BMD) were identified from the Manitoba Bone Density Program, Canada (n = 51,327), 1996-2011. Mean household income, extracted from 2006 census files, was categorized into quintiles. Ten-year fracture probabilities were calculated using FRAX Canada. Incident non-traumatic fractures were studied in relation to income quintile in adjusted Cox proportional hazards models. We compared observed versus predicted fractures with and without a competing mortality framework.

RESULTS

During mean 6.2 ± 3.7 years of follow up, there were 6,392 deaths, 3,723 women with ≥1 major osteoporotic fracture (MOF), and 1,027 with hip fractures. Lower income was associated with higher risk for death, MOF, and hip fracture in adjusted models (all p < 0.005). More women in income quintile 1 (lowest) versus quintile 5 experienced death (19 vs. 8%), MOF (10 vs. 6%), or hip fracture (3.0 vs. 1.3 %) (all p ≤ 0.001). Adjustment for competing mortality mitigated the effect of SES on FRAX calibration, and good calibration was observed. FRAX provided good fracture discrimination for MOF and hip fracture within each income quintile (all p < 0.001). Area under the curve was slightly lower for income quintiles 1 versus 5 for FRAX with BMD to predict MOF (0.68, 95% CI 0.66-0.70 vs. 0.71, 95% CI 0.69-0.74) and hip fracture (0.79, 95% CI 0.76-0.81 vs. 0.87, 95% CI 0.84-0.89).

CONCLUSION

Increased fracture risk in individuals of lower income is offset by increased mortality. Under a competing mortality framework, FRAX provides robust fracture prediction and calibration regardless of SES.

Is lower income associated with an increased likelihood of qualification for treatment for osteoporosis in Canadian women?

We examined whether low income was associated with an increased likelihood of treatment qualification for osteoporotic fracture probability determined by Canada FRAX in women aged ≥50 years. A significant negative linear association was observed between income and treatment qualification when FRAX included bone mineral density (BMD), which may have implications for clinical practice.

INTRODUCTION

Lower income has been associated with increased fracture risk. We examined whether lower income in women was associated with an increased likelihood of treatment qualification determined by Canada FRAX®.

METHODS

We calculated 10-year FRAX probabilities in 51,327 Canadian women aged ≥50 years undergoing baseline BMD measured by dual energy x-ray absorptiometry 1996-2001. FRAX probabilities for hip fracture ≥3% or major osteoporotic fracture (MOF) ≥20 % were used to define treatment qualification. Mean household income from Canada Census 2006 public use files was used to categorize the population into quintiles. Logistic regression analyses were used to model the association between income and treatment qualification.

RESULTS

Percentages of women who qualified for treatment based upon high hip fracture probability increased linearly with declining income quintile (all p trend <0.001), but this was partially explained by older age among lower income quintiles (p trend <0.001). Compared to the highest income quintile, women in the lowest income quintile had a greater likelihood of treatment qualification based upon high hip fracture probability determined with BMD (age-adjusted odds ratio [OR], 1.34; 95% confidence intervals (CI), 1.23-1.47) or high MOF fracture probability determined with BMD (age-adjusted OR, 1.31; 95% CI, 1.18-1.46). Differences were nonsignificant when FRAX was determined without BMD, implying that BMD differences may be the primary explanatory factor.

CONCLUSIONS

FRAX determined with BMD identifies a larger proportion of lower income women as qualifying for treatment than higher income women.

The mediating role of dietary factors and leisure time physical activity on socioeconomic inequalities in body mass index among Australian adults

BACKGROUND

The relationship between socioeconomic position and obesity has been clearly established, however, the extent to which specific behavioural factors mediate this relationship is less clear. This study aimed to ascertain the contribution of specific dietary elements and leisure-time physical activity (LTPA) to variations in obesity with education in the baseline (1990-1994) Melbourne Collaborative Cohort Study (MCCS).

METHODS

18, 489 women and 12, 141 men were included in this cross-sectional analysis. A series of linear regression models were used in accordance with the products of coefficients method to examine the mediating role of alcohol, soft drink (regular and diet), snacks (healthy and sweet), savoury items (healthy and unhealthy), meeting fruit and vegetable guidelines and LTPA on the relationship between education and body mass index (BMI).

RESULTS

Compared to those with lowest educational attainment, those with the highest educational attainment had a 1 kg/m2 lower BMI. Among men and women, 27% and 48%, respectively, of this disparity was attributable to differences in LTPA and diet. Unhealthy savoury item consumption and LTPA contributed most to the mediated effects for men and women. Alcohol and diet soft drink were additionally important mediators for women.

CONCLUSIONS

Diet and LTPA are potentially modifiable behavioural risk factors for the development of obesity that contribute substantially to inequalities in BMI. Our findings highlight the importance of specific behaviours which may be useful to the implementation of effective, targeted public policy to reduce socioeconomic inequalities in obesity.

Relationship between needs driving eating occasions and eating behavior in midlife women

The purpose of this cross-sectional study was to determine the relationship between type of eating occasion based on need state segments experienced by 200 midlife women (46+/-6 years) and food group, nutrient, and energy intake. Women completed an Eating Occasion Questionnaire for 3 eating occasions over a 3-day period for which they maintained diet records. Cluster analysis segmented 559 eating occasions into six need states. Energy, total fat, and cholesterol consumption per occasion were highest in "routine family meal" occasions of which more than 60% were dinner and eaten at home with their children. The percentage of eating occasions in which fruits/vegetables were eaten was also highest in "routine family meal," followed by "healthy regimen." More than half of "indulgent escape" eating occasions occurred away from home and about one-third were experienced as a snack. Saturated fat and sweets intakes were the highest in the "indulgent escapes" occasions. Eating occasions experienced by women according to needs surrounding the occasion should be considered when developing tailored interventions to improve intake.