Cecilia Albala

Obesity trends and determinant factors in Latin America

Obesity rates have increased markedly in Latin America, especially during the last 10-15 years, becoming a public health problem in most countries. Prevalence of obesity among preschool children remains low, while among schoolchildren it has increased considerably. Prevalence is high in the adult population, especially among women with less schooling. In developed populations, obesity occurs more frequently among the poor; the opposite occurs in less developed societies, where in households undergoing nutritional transition, underweight can coexist with obesity. The most important determinant factors involved in the increasing obesity prevalence are fetal and infant nutritional conditions (stunting), education and socioeconomic conditions, dietary changes (especially increased total energy intake), and physical inactivity. Because chronic diseases are the main causes of death in the Region and obesity is one of the main risk factors for these diseases, policies to improve economic and educational levels with the implementation of health promotion and prevention should be a priority in every country.

Trends in overweight and obesity prevalence in Chilean children: comparison of three definitions

Objective: To compare trends in prevalence of overweight and obesity among Chilean children using three different criteria.Methods: Descriptive cross-sectional school-based study to analyse these trends in 6-y-old boys and girls who entered first grade in 1987, 1990, 1993, 1996 and 2000. Gender-specific prevalence of overweight and obesity were determined with three criteria: weight for height (W-H) Z-scores compared to NCHS 1977; present reference used by the Ministry of Health; and body mass index (BMI) compared to the revised US CDC Growth Charts with cut-off values of P85-95 and P-95 and IOTF reference with cut-offs extrapolated from an adult BMI of 25 and 30.Results: The prevalence of overweight determined by W-H (WHO) increased from 15% in 1987 to 20% in 2000 for boys and from 17.2 to 21.8% for girls. With BMI-CDC, the increase was from 13.2 to 19.2% for boys and 12 to 18.5% for girls. With BMI-IOTF, rates were very similar. Prevalence of obesity using W-H (WHO) increased from 6.5% in 1987 to 17% in 2000 for boys and from 7.8 to 18.6% for girls. Using BMI-CDC, the increase was from 5.1 to 14.7% for boys and from 4 to 15.8% for girls; using BMI-IOTF prevalence estimates were much lower.Conclusions: Obesity prevalence in children has increased over time, and trends are similar independent of criteria. The reference used to define prevalence is important since it provides different estimates. Policy makers should be aware that a spurious drop in prevalence may appear if the IOTF reference is compared to the other criteria.

Prevalence of dementia in Latin America: a collaborative study of population-based cohorts

BACKGROUND Dementia is becoming a major public health problem in Latin America (LA), yet epidemiological information on dementia remains scarce in this region. This study analyzes data from epidemiological studies on the prevalence of dementia in LA and compares the prevalence of dementia and its causes across countries in LA and attempts to clarify differences from those of developed regions of the world. METHODS A database search for population studies on rates of dementia in LA was performed. Abstracts were also included in the search. Authors of the publications were invited to participate in this collaborative study by sharing missing or more recent data analysis with the group. RESULTS Eight studies from six countries were included. The global prevalence of dementia in the elderly (> or =65 years) was 7.1% (95% CI: 6.8-7.4), mirroring the rates of developed countries. However, prevalence in relatively young subjects (65-69 years) was higher in LA studies The rate of illiteracy among the elderly was 9.3% and the prevalence of dementia in illiterates was two times higher than in literates. Alzheimers disease was the most common cause of dementia. CONCLUSIONS Compared with studies from developed countries, the global prevalence of dementia in LA proved similar, although a higher prevalence of dementia in relatively young subjects was evidenced, which may be related to the association between low educational level and lower cognitive reserve, causing earlier emergence of clinical signs of dementia in the LA elderly population.

Colon cancer in Chile before and after the start of the flour fortification program with folic acid.

Background Folate depletion is associated with an increased risk of colorectal carcinogenesis. A temporal association between folic acid fortification of enriched cereal grains and an increase in the incidence of colorectal cancer in the USA and Canada has, however, been recently reported. Aim To compare the rates of hospital discharges owing to colon cancer in Chile before and after the start of the mandatory flour fortification program with 220 μg of synthetic folic acid/100 g of wheat flour. Methods Cancer and cardiovascular hospital discharge rates were compared using rate ratios between two study periods, 1992–1996, before folic acid fortification and 2001–2004, after the flour fortification with folic acid was established in the country. Standard errors of the log rate ratio to derive confidence intervals, and to test the null hypothesis of no difference, were calculated. Results The highest rate ratio between the two periods was for colon cancer in the group aged 45–64 years (rate ratio: 2.6, confidence interval: 99% 2.93–2.58) and in the 65–79 years (rate ratio: 2.9, confidence interval: 99% 3.25–2.86). Conclusion Our data provide new evidence that a folate fortification program could be associated with an additional risk of colon cancer.

Epidemiological transition in Latin America: The case of Chile

To describe Chiles stage of epidemiological transition, a descriptive study of the changes to the demographic and economic profile of this country during the last 20 years is presented. The decline in the total fertility rate from 3.4 in 1970 to 2.6 in 1992 and the important decrease in general and infant mortality rate has led to an increase of life expectancy of 8 years for men and 9 years for women. This has resulted in changes to the age structure and causes of mortality and morbidity of the population. A reduction of 82% in the proportion of deaths among children < 1 year and a 73% increase of mortality amongst those 65 years and older can be observed. In line with these changes non-communicable diseases have increased from 53.7% of all deaths in 1970 to 74.9% in 1991. In the same period mortality rates from cardiovascular causes have decreased from 189.6 to 161.1 per 100,000 population, whilst their relative proportion of all causes has increased from 22.3% to 29%. High prevalence of risk factors should lead to a significant increase of chronic diseases in future years. Regarding morbidity, a high incidence rate for tuberculosis persists together with an increase of infections of the digestive system and of sexually transmitted diseases. A decrease in the rates of diseases preventable by immunisation has been noted. It is concluded that, as defined by population mortality statistics, Chile is in a post-transition stage but with a persistence of some infectious diseases corresponding to a transitional stage of development.

Low prevalence of type 2 diabetes despite a high average body mass index in the aymara natives from chile

The aim of this study was to estimate the prevalence of type 2 diabetes mellitus (DM2), impaired glucose tolerance (IGT), and the frequency of dyslipidemia, obesity, and hypertension in the rural Aymara population from Northern Chile. In this cross-sectional study, 196 Aymara adult subjects were characterized with respect to their reported physical activity, fasting plasma glucose levels, insulin concentrations, blood pressures, body mass indexes, and plasma lipid profiles. The participants also underwent a 2-h oral glucose tolerance test. The diagnostic criteria for DM2 and IGT followed those of the World Health Organization. The overall prevalence of DM2 was estimated as 1.5% (95% confidence interval: 0.3--4.5). Overall prevalence of IGT was calculated as 3.6% (1.5--7.3). The occurrence of obesity and dyslipidemia was relatively high in the Aymara population, although the frequency of sedentary habits, and the prevalence of hypertension were low. In conclusion, the prevalence of DM2 in the rural Aymara population living at high altitudes in Northern Chile, was much lower than that of other Amerindian groups that adopted lifestyles from industrialized Western societies. Despite a relatively high prevalence of a body mass index of at least 30 kg/m(2), especially in women (23.5%), high physical activity levels and low plasma-insulin concentrations may have been responsible in part for the low prevalence of DM2 in the Aymara population.

Prevalence of Type 2 Diabetes and Obesity in Rural Mapuche Population From Chile

The aim of this study was to estimate the prevalence of Type 2 diabetes, impaired glucose tolerance (IGT), and obesity in the Mapuche natives from rural areas in Chile. This cross-sectional study involved men (n = 95) and women (n = 224) older than 20 y from an aboriginal ethnic group (Mapuches), residing in rural communities from the south of Chile. Prevalence of Type 2 diabetes and IGT was calculated according to the World Health Organization criteria. Data on age, degree of ancestral purity, obesity, and hypertension were also obtained. The prevalence of Type 2 diabetes in rural Mapuche natives was estimated as 3.2% (95% CI: 0.7--9.0) in men and 4.5% (95% CI: 2.2--8.1) in women. The overall prevalence of obesity was 56.1% (95% CI: 50.5--61.6): 40.0% (95% CI: 30.1--40.8) in men and 62.9% (95% CI: 56.3--69.3) in women (P value < 0.001). These data suggest that the prevalence of obesity and Type 2 diabetes has been increasing during recent years in the Mapuche communities. The prevalence estimated in this study is higher than that reported 15 y ago. This suggests an important role of lifestyle changes as a possible explanation for epidemiologic transition.

Grandparenting and psychosocial health among older Chileans: A longitudinal analysis

Objectives: To investigate factors associated with Chilean grandparents’ provision of help to grandchildren and associations between provision of such help and grandparents’ mental well-being two years later. Methods: Data are drawn from a representative sample of 2000 people aged 66–68 resident in low- or middle-income areas of Santiago who were surveyed in 2005 and re-interviewed two years later. Multivariable analyses were used to investigate factors associated with provision of help to grandchildren at baseline and associations between providing such help and life satisfaction, SF36-Mental Component Summary scores, and depression two years later. Results: 41% of grandparents lived with one or more grandchildren and over half provided four or more hours per week of help to grandchildren. Models controlling for baseline mental health, grandchild characteristics, marital and household characteristics, socio-economic status and functional health showed that grandfathers who provided four or more hours per week of help to grandchildren had better life satisfaction two years later and that those providing material help had higher SF36 MCS scores at follow-up. Grandmothers providing four or more hours of help a week had lower risks of depression. Conclusion: Older Chileans make important contributions to their families through the provision of help to grandchildren and these appear to have some benefits for their own psychosocial health. Gender differences in the pattern of associations may reflect differences in overall family responsibilities and merit further investigation.

Indicadores antropométricos, composición corporal y limitaciones funcionales en ancianos

Background: Functional limitations limit the independence and jeopardize the quality of life of elderly subjects. Aim: To assess the association between anthropometric measures and body composition with functional limitations in communityliving older people. Material and Methods: Cross-sectional survey of 377 people ≥65 years old (238 women), randomly selected from the SABE/Chile project. Complete anthropometric measurements were done. Handgrip muscle strength was measured using dynamometers. Body composition was determined using Dual-Energy X-Ray Absorptiometry. Functional limitations were assessed using self reported and observed activities. Results: Body mass index was strongly associated with fat mass (men r =0.87; women r =0.91) and with lean mass (men r =0.55; women r =0.62). Males had significantly greater lean mass (48.9 kg vs 34.9 kg), and bone mass than females (2.6 kg vs 1.8 kg) and women had higher fat mass than men (26.3 kg vs 22.9 kg). The prevalence of functional limitations was high, affecting more women than men (63.7% vs 37.5%, p <0.01). Functional limitations were associated with lower handgrip strength in both sexes. In the multiple regression models, with functional limitations as dependent variable and anthropometric measures as contributing variables, only hand grip strength had a significant association (negative) with functional limitation in both genders. Age was also a significant risk factor for functional limitations among women. Conclusions: Hand grip strength was strongly and inversely associated with functional limitations. Handgrip dynamometry is an easy, cheap and low time-consuming indicator for the assessment of functional limitations and the evaluation of geriatric interventions aimed to improve functional ability (Rev Med Chile 2007; 135: 846-54). (Key words: Aged; Anthropometry; Body composition; Frail elderly)

Vitamin B-12 treatment of asymptomatic, deficient, elderly Chileans improves conductivity in myelinated peripheral nerves, but high serum folate impairs vitamin B-12 status response assessed by the combined indicator of vitamin B-12 status

BACKGROUND It is uncertain whether vitamin B-12 supplementation can improve neurophysiologic function in asymptomatic elderly with low vitamin B-12 status or whether folate status affects responses to vitamin B-12 supplementation. OBJECTIVE We assessed the effects of a single intramuscular injection of 10 mg vitamin B-12 (which also contained 100 mg vitamin B-6 and 100 mg vitamin B-1) on vitamin B-12 status and neurophysiologic function in elderly community-dwelling Chileans with low serum vitamin B-12 concentrations who were consuming bread fortified with folic acid. DESIGN A pretreatment and posttreatment study was conducted in 51 participants (median ± SD age: 73 ± 3 y; women: 47%) with serum vitamin B-12 concentrations <120 pmol/L at screening. Vitamin B-12 status was defined by combining vitamin B-12, plasma total homocysteine (tHcy), methylmalonic acid (MMA), and holotranscobalamin into one variable [combined indicator of vitamin B-12 status (cB-12)]. The response to treatment was assessed by measuring cB-12 and neurophysiologic variables at baseline and 4 mo after treatment. RESULTS Treatment increased serum vitamin B-12, holotranscobalamin, and cB-12 (P < 0.001) and reduced plasma tHcy and serum MMA (P < 0.001). Treatment produced consistent improvements in conduction in myelinated peripheral nerves; the sensory latency of both the left and right sural nerves improved on the basis of faster median conduction times of 3.1 and 3.0 ms and 3.3 and 3.4 ms, respectively (P < 0.0001). A total of 10 sensory potentials were newly observed in sural nerves after treatment. Participants with high serum folate at baseline (above the median, ≥33.9 nmol/L) had less improvement in cB-12 (P < 0.001) than did individuals whose serum folate was less than the median concentration (i.e., with a concentration <33.9 nmol/L). CONCLUSION Asymptomatic Chilean elderly with poor vitamin B-12 status displayed improved conductivity in myelinated peripheral nerves after vitamin B-12 treatment and an interaction with folate status, which was detected only with the use of cB-12. This trial was registered at www.controlled-trials.com as ISRCTN02694183.