The Prevalence of Obesity and Its Determinants in Urban and Rural Aging Mexican Populations

LERMAN-GARBER, ISRAEL, ANTONIO R. VILLA, CRISTINA LLACA MARTINEZ, LETICIA CERVANTES TURRUBIATEZ, CARLOS A. AGUILAR SALINAS, VILLAGRA LUCY, BELIA WONG, JUAN C. LÓPEZ ALVARENGA, FRANCISCO GÓMEZ PÉREZ, AND LUIS MIGUEL GUTIERREZ ROBLEDO. The prevalence of obesity and its determinants in urban and rural older mexican populations. Obes Res. Objective: To determine the prevalence of obesity and its association to different variables in urban and rural older Mexican populations. Methods and Procedures: A cross-sectional study of three different Mexican communities. A total of 121 men and 223 women 60 years and older and 93 men and 180 women aged 35 to 59 years old were selected randomly for inclusion in the survey. A personal interview assessed demographic information, personal medical history and functional status and a 24-hour diet recall was obtained. The physical examination included anthropometric and blood pressure measurements. A fasting blood sample was obtained for measurements of lipids, insulin and glucose. Results: Obesity was highly prevalent in women, in individuals from the urban communities and diminished with advancing age. A BMI ≥30 kg/m² was observed in 23. 6% younger vs. 15. 6% older adult men (p = 0. 21) and 28. 4% younger vs. 19. 7% older adult women (p = 0. 06). Conclusions: The present survey confirms the high prevalence of obesity in the Mexican urban population that declines with advanced age. Studies in elderly population must consider the bias produced by increased early mortality in those individuals with a more unfavorable risk profile. The association of obesity with other variables was estimated using a stepwise multivariate logistic regression, increased insulin levels [Odds Ratio (OR) 1. 68, p = 0. 006] and living in an urban area (OR 5. 90, p <0. 007) were variables independently associated to obesity in adult older individuals. In the younger adults, obesity was associated with hypertension (OR 2. 74, p<0. 0009), higher insulin levels (OR 1. 31, p<0. 03) and central adiposity (OR 2. 97, p = 0. 05), these relationship were not observed with gender, distribution of food or alcohol intake or other coronary risk factors.     

Long-term adaptive response to dietary protein of hexose monophosphate shunt dehydrogenases in rat kidney tubules

We have studied the effects of several different macronutrients on the kinetic behaviour of rat renal glucose 6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH). Rats were meal-fed with high-carbohydrate/low-protein, high-protein/low-carbohydrate and high-fat diets. High-protein increased renal G6PDH and 6PDGH activities by 66 per cent and 70 per cent respectively, without significantly changing the Km values of either and each Hexose monophosphate dehydrogenase activity increased steadily, reaching a significant difference on day 4. A rise in carbohydrate or fat in the diets, produced no significant change in either the activity or the kinetic parameters, Vmax and Km of the two dehydrogenases. In addition, the administration of a high-protein diet for 8 days significantly increased both the pentose phosphate pathway flux (92.6 per cent) and the kidney weigth (35 per cent), whereas no significant changes in these parameters were found when the animals were treated with the other diets. Our results suggest that an increase in the levels of dietary protein induces a rise in the intracellular levels of these enzymes. The possible role of this metabolic pathway in the kidneys under these nutritional conditions is also discussed.     

Hypothalamic Synaptogenesis and Its Relationship with the Maturation of Hormonal Secretion

1. Information obtained during the last decade has demonstrated that hypothalamic neurons release a wide variety of neuroactive substances, such as neurotransmitters, mostly monoamines and amino acids, and neuromodulators such as the peptides vasopressin (AVP) and oxytocin (OXT) and hypophysial releasing hormones.2. Synapse formation between hypothalamic neurons was followed at different timeswithin a given nucleus and among different nuclei during development of the mouse hypo-thalamus.3. The amounts of various neurotransmitters and hormones were determined at various stages of development.4. A correlation is presented of the biochemical and ultrastructural features and theirfunctional implications during maturation.