Sex differences in obesity prevalence and cardiometabolic factors among Western Alaska Native people

BACKGROUND AND AIMS

Obesity is associated with increased risks of cardiovascular disease, type 2 diabetes, and other chronic diseases. Prevalence estimates for metabolic disorders are well documented in many populations, but Alaska Native groups are understudied. The Western Alaska Tribal Collaborative for Health Study combines data from three Alaska Native study cohorts to assess differences in obesity prevalence and associations with cardiometabolic risk factors by sex.

METHODS AND RESULTS

Analyses were based upon a sample of 3985 adult Yup'ik and Inupiat participants with a mean age of 40 years. Prevalence of obesity and metabolic risk factors was assessed according to nationally recognized guidelines. Regression analysis was used to evaluate the association between obesity and cardiometabolic risk factors, including lipids, blood pressure and glucose. The prevalence of obesity (BMI ≥ 30) was significantly higher in women (40%) than men (20%). Only 18.6% of men had a waist circumference (WC) > 102 cm, while 58% of women had a WC > 88 cm (p < 0.001). Women had higher mean HDL-C and triglyceride levels compared to men, while systolic and diastolic blood pressure, LDL-C, and glucose means were higher in men than in women. In multivariate analyses, BMI and WC were significantly associated with all of the cardiometabolic risk factors, although these associations were more pronounced in men than women.

CONCLUSION

The high prevalence of obesity and central adiposity among AN women is an important public health concern. Differences in associations between obesity and cardiometabolic risk factors by sex warrants further investigation to develop effective intervention programs.

Stress, social support, and schizophrenia. Discussion

Three review articles (Dohrenwend and Egri 1981; Hammer 1981; Lin, Dean, and Ensel 1981) addressing various aspects of stress, social support, and schizophrenia are discussed. Phenomena so complex as these, involving simultaneously chemical, biological, physiological, social, and cultural systems, may require a different research paradigm than the simple unidirectional causal model used in most current studies. Perhaps a mutual causal paradigm will ultimately enhance our understanding by permitting more realistic assumptions about social processes. Three distinct network models are outlined: network as a set of links, network as generated structure, and flow network. Understanding of social support systems might be enhanced by the analysis of interpersonal resources in terms of categories discovered by Uriel and Edna Foa: love, status, information, services, goods, money. It is to be hoped that we will soon be able to work with methods and models that do not require oversimplifying assumptions.

The aortic sinus vortex

This paper describes an analytic and a numerical method for the aortic sinus problem. Both methods are based on the dynamics of point vortices, and both exploit a particular conformal mapping from a model aortic sinus to the upper half plane. The analytic description is based on an isolated point vortex in equilibrium with a free stream. This inviscid model is used to study the stability of the aortic sinus vortex and to elucidate the mechanism of aortic valve closure, but it cannot be used to study the formation of the sinus vortex and it gives a somewhat incorrect picture of the flow pattern. These difficulties are overcome by the introduction of a numerical method for the aortic sinus problem with fluid viscosity. We use Chorin's vortex method combined with conformal mapping. The conformal mapping approach gives an explicit formula for the vortex velocities and it resolves the singularities associated with the corners of the domain. This method is then used to study the formation of the sinus vortex and to confirm the predictions of the point vortex model with respect to the role of the vortex in valve closure.