Changes in serum lipids with change and fluctuation in body mass index and body fat distribution in Mexican Americans with type 2 diabetes

This dissertation was written in the format of three journal articles. Paper 1 examined the influence of change and fluctuation in body mass index (BMI) over an eleven-year period, on changes in serum lipid levels (total, HDL, and LDL cholesterol, triglyceride) in a population of Mexican Americans with type 2 diabetes. Linear regression models containing initial lipid value, BMI and age, BMI change (slope of BMI), and BMI fluctuation (root mean square error) were used to investigate associations of these variables with change in lipids over time. Increasing BMI over time was associated with gains in total and LDL cholesterol and triglyceride levels in women. Fluctuation of BMI was not associated with detrimental lipid profiles. These effects were independent of age and were not statistically significant in men. In Mexican-American women with type 2 diabetes, weight reduction is likely to result in more favorable levels of total and LDL cholesterol and triglyceride, without concern for possible detrimental effects of weight fluctuation. Weight reduction may not be as effective in men, but does not appear to be harmful either. ^ Paper 2 examined the associations of upper and total body fat with total cholesterol, HDL and LDL cholesterol, and triglyceride levels in the same population. Multilevel analysis was used to predict serum lipid levels from total body fat (BMI and triceps skinfold) and upper body fat (subscapular skinfold), while controlling for the effects of sex, age and self-correlations across time. Body fat was not strikingly associated with trends in serum lipid levels. However, upper body fat was strongly associated with triglyceride levels. This suggests that loss of upper body fat may be more important than weight loss in management of the hypertriglyceridemia commonly seen in type 2 diabetes. ^ Paper 3 was a review of the literature reporting associations between weight fluctuation and lipid levels. Few studies have reported associations between weight fluctuation and total, LDL, and HDL cholesterol and triglyceride levels. The body of evidence to date suggests that weight fluctuation does not strongly influence levels of total, LDL and HDL cholesterol and triglyceride. ^

Cross-sectional study examining the role of acculturation in self-reported hypertension among Mexican Americans in Harris County, Texas

The objective of this secondary analysis was to examine the role of acculturation and self-reported hypertension in a Mexican-American cohort from Harris County, Texas. Specifically, we examined the acculturation measures of language-based Bidimensional Acculturation Scale (BAS), nativity, and length of United States (U.S) residency. Of 6,229 participants aged 40 and older, 38.0% self-reported hypertension at baseline. ^ Multiple logistic regression was used to estimate the prevalence odds ratios (pOR) for the association of each acculturation measure and hypertension while controlling for confounding. When adjusted for age, gender, body mass index, number of comorbidities, and family history of hypertension, U.S.-born participants were 1.37 times more likely to report having hypertension compared to Mexico-born participants (95% CI: 1.21, 1.55). Similarly, immigrants residing in the U.S. for more than 20 years had an adjusted pOR of 1.40 (95% CI: 1.16, 1.70) as compared to immigrants living in the U.S. for less than 10 years. ^ In conclusion, individuals who were born in the U.S. or emigrated to the U.S. over 20 years ago were more likely to report having hypertension compared to individuals born in Mexico or compared to those who emigrated more recently to the U.S. This study will contribute to the literature in demonstrating the need for more initiatives in prevention of cardiovascular disease, specifically hypertension, in the acculturating Mexican American population.^