Edgar Denova-Gutiérrez

The effect of vitamin D supplementation on serum lipids in postmenopausal women with diabetes: A randomized controlled trial

BACKGROUND & AIMS Dyslipidemia is a risk factor for cardiovascular disease that has become an increasing public health problem. Dyslipidemia is especially relevant in vulnerable populations such as postmenopausal women. Low serum levels of 25-hydroxyvitamin D have been associated with an unfavourable lipid profile. Due to contradictory findings from intervention trials, we investigated the effect of vitamin D supplementation on serum lipids in postmenopausal women with type 2 diabetes. METHODS A total of 104 postmenopausal women with type 2 diabetes were randomly assigned in a double-blind manner to 1 of 2 groups taking a daily tablet for 6 months: a group consuming 4000 IU tablets of a vitamin D supplement (vitamin D group n = 52) or a group consuming placebo tablets (placebo group n = 52). RESULTS The study was completed by 99 participants. However, as the analysis was based on an intention-to-treat approach, all 104 women were included in the final analysis. In the vitamin D group mean serum levels of 25(OH)D3 improved significantly at the end of the follow-up period (+25.5 nmol/L; P = <0.001). Our findings revealed no significant changes in low density lipoproteins, high density lipoproteins and total cholesterol concentrations, but did identify a greater decrease in serum triglycerides in the vitamin D group. The average effect of supplementation on the treated group was -34.24 mg/dL (P = 0.021), while the average treatment effect was -31.8 mg/dL (P = 0.023). CONCLUSIONS Our results suggest that supplementation with vitamin D (4000 IU/d) may have a beneficial effect on serum triglyceride levels without otherwise affecting levels of other lipids. TRIAL REGISTRATION clinicaltrial.gov; identifier NCT01019642.

Association between Dietary Patterns and Insulin Resistance in Mexican Children and Adolescents

Background/Objective: Insulin resistance (IR) is a metabolic disorder that is increasing worldwide and has been associated with several negative health outcomes. The aim of this study was to evaluate the relationship between different dietary patterns and IR among Mexican children and adolescents. Methods: We performed a cross-sectional analysis on baseline data from Mexican children and adolescents aged 7–18 years participating in the Health Workers Cohort Study. We included 916 children and adolescents of both sexes. Fasting serum glucose and insulin levels were determined by standardized methods. We defined IR using the homeostasis model assessment (HOMA) as ≥3.5. Factor analysis was used to identify dietary patterns. The associations of interest, those between IR and dietary patterns, were analyzed with multiple logistic regression models. Results: IR prevalence was 20.3% among girls and boys aged 7–18 years, for whom the prevalence of overweight and obesity was 29.7%. We identified 3 major dietary patterns in this group: ‘Western’, ‘prudent’ and ‘high protein/fat’. For the purposes of this analysis we compared the upper versus the lower quintile of each dietary pattern. Independently of other covariates, participants in the highest quintile of the Western pattern had 92% greater odds of IR (OR 1.92, 95% CI: 1.08–3.43) compared with those in the lowest quintile. Conclusions: These findings support the hypothesis that high carbohydrate diets like our Western dietary pattern may increase IR in young people. This result emphasizes the importance of preventive nutrition interventions geared toward Mexican children and adolescents.

Physical activity and reduced risk of depression: results of a longitudinal study of Mexican adults.

OBJECTIVE To evaluate the effect of physical activity (PA) on the risk of depression among Mexican adults over a 6-year follow-up period. METHOD We evaluated longitudinal data from the Health Worker Cohort Study, which follows employees of the Mexican Institute for Social Security in Morelos State, Mexico, over time. Depressive symptoms and PA were assessed at baseline and at a follow-up measurement 6 years later. The study population was free of depressive symptomatology at baseline, as assessed by the Center for Epidemiological Studies-Depression Scale (CES-D). After 6 years, the CES-D was completed once again by the participants to estimate their risk of depression based on the different PA patterns they reported during the follow-up period. PA was estimated using a questionnaire that has been applied in similar longitudinal studies and has been validated in Spanish, with metabolic equivalents (METs) as the unit of measurement. We identified three PA patterns: highly active, moderately active, and inactive. The relative risk of depression (CES-D score ≥ 16 points) was estimated using multivariate logistical regression analysis according to the PA patterns at a follow-up measurement 6 years later. RESULTS The incidence of depression after 6 years was higher among inactive participants (16.5%) than among those with an active PA pattern (10.6%). We found that more active PA patterns have an important protective effect against depression. The odds ratio (OR) for the more active PA patterns was 0.46, 95% confidence interval (CI) [0.25, 0.87], and for individuals with a moderately active PA pattern, the OR was 0.57, 95% CI [0.34, 0.93]. These ORs were obtained after adjusting for confounding variables and baseline PA levels. CONCLUSION Our results indicate that PA may reduce risk of depression in Mexican adults. These findings have potential applications for depression prevention programs in target populations with similar social and cultural contexts.

Validity of a food frequency questionnaire to assess food intake in Mexican adolescent and adult population

Objective: To assess the validity of a 140-item semiquantitative food frequency questionnaire (SFFQ), in Mexican adolescents and adults. Materials and methods: Dietary intakes using a SFFQ and two 24-hour dietary recalls (24DRs), in nonconsecutive days during the same week were measured from 178 adolescents and 230 adults participating in the Mexican National Health and Nutrition Survey-2012.Validity was evaluated using correlation coefficients (CC),deattenuated CC, linear regression models, cross-classification analysis, and the Bland-Altman method. Results: In adults, deattenuated correlation coefficients between the SFFQ and the 24DRs ranged from 0.30 for folate to 0.61 for saturated fat. In addition, 63% adults and 62% adolescents were classified in the same and adjacent quartile of nutrient intake when comparing data from SFFQ and 24DRs. Conclusions: The SFFQ had moderate validity for energy, macronutrients and micronutrients. It also had good validity to rank individuals according to their dietary intake of different nutrients.

A workplace physical activity program at a public university in Mexico can reduce medical costs associated with type 2 diabetes and hypertension

OBJECTIVE To assess the impact of a workplace leisure physical activity program on healthcare expenditures for type 2 diabetes and hypertension treatment. MATERIAL AND METHODS We assessed a workplace programs potential to reduce costs by multiplying the annual healthcare costs of patients with type 2 diabetes and hypertension by the population attributable risk fraction of non-recommended physical activity levels. Feasibility of a physical activity program was assessed among 425 employees of a public university in Mexico. RESULTS If 400 sedentary employees engaged in a physical activity program to decrease their risk of diabetes and hypertension, the potential annual healthcare cost reduction would be 138 880 US dollars. Each dollar invested in physical activity could reduce treatment costs of both diseases by 5.3 dollars. CONCLUSIONS This research meets the call to use health economics methods to re-appraise health priorities, and devise strategies for optimal allocation of financial resources in the health sector.

Simulation Model of the Impact of Biofortification on the Absorption of Adequate Amounts of Zinc and Iron among Mexican Women and Preschool Children

Background Biofortification is an agricultural process that attempts to increase the iron and zinc content of staple food crops. Improving the absorption of zinc and iron could contribute to reducing the high rates of deficiency of these micronutrients in developing-country settings. Objective To simulate the effects of biofortification of staple food crops (maize, wheat, rice, and beans) on the absorption of zinc and iron among women and children in Mexico. Methods We analyzed dietary data from the 1999 Mexican National Nutrition Survey. On the basis of the intake of the four staple food crops and the increase in zinc and iron content that could be achieved by conventional breeding in the short term, the prevalence of inadequacy in the amounts of absorbed zinc and iron was determined. The mean increase in the amounts of absorbed zinc and iron was compared according to rural and urban residence and according to region of the country. Results In rural areas, simulated biofortification of maize resulted in a reduction in the prevalence of absorption of inadequate amounts of zinc of 47% in children and 56% in women but had no effect on the prevalence of absorption of inadequate amounts of iron. The increase in zinc absorption was greater in rural populations and in the Central and Southern regions (p < .05). Conclusions Biofortification of maize could significantly improve zinc absorption among children and women in Mexico living in areas most vulnerable to zinc deficiency. Studies of the biological impact of biofortified maize on zinc status are warranted.

Health workers cohort study: methods and study design

Objective: To examine different health outcomes that are associated with specific lifestyle and genetic factors. Materials and methods: From March 2004 to April 2006, a sample of employees from three different health and academic institutions, as well as their family members, were enrolled in the study after providing informed consent. At baseline and follow-up (2010-2013), participants completed a self-administered questionnaire, a physical examination, and provided blood samples. Results: A total of 10 729 participants aged 6 to 94 years were recruited at baseline. Of these, 70% were females, and 50% were from the Mexican Social Security Institute. Nearly 42% of the adults in the sample were overweight, while 20% were obese. Conclusion: Our study can offer new insights into disease mechanisms and prevention through the analysis of risk factor information in a large sample of Mexicans.

Accuracy of body fat percent and adiposity indicators cut off values to detect metabolic risk factors in a sample of Mexican adults

BackgroundAlthough body fat percent (BF%) may be used for screening metabolic risk factors, its accuracy compared to BMI and waist circumference is unknown in a Mexican population. We compared the classification accuracy of BF%, BMI and WC for the detection of metabolic risk factors in a sample of Mexican adults; optimized cutoffs as well as sensitivity and specificity at commonly used BF% and BMI international cutoffs were estimated. We also estimated conditional BF% means at BMI international cutoffs.MethodsWe performed a cross-sectional analysis of data on body composition, anthropometry and metabolic risk factors(high glucose, high triglycerides, low HDL cholesterol and hypertension) from 5,100 Mexican men and women. The association between BMI, WC and BF%was evaluated with linear regression models. The BF%, BMI and WC optimal cutoffs for the detection of metabolic risk factors were selected at the point where sensitivity was closest to specificity. Areas under the ROC Curve (AUC) were compared among classifiers using a non-parametric method.ResultsAfter adjustment for WC, a 1% increase in BMI was associated with a BF% rise of 0.05 percentage points (p.p.) in men (P < 0.05) and 0.25 p.p. in women (P < 0.001). At BMI = 25.0 predicted BF% was 27.6 ± 0.16 (mean ± SE) in men and 41.2 ± 0.07 in women. Estimated BF% cutoffs for detection of metabolic risk factors were close to 30.0 in men and close to 44.0 in women. In men WC had higher AUC than BF% for the classification of all conditions whereas BMI had higher AUC than BF% for the classification of high triglycerides and hypertension. In womenBMI and WC had higher AUC than BF% for the classification of all metabolic risk factors.ConclusionsBMI and WC were more accurate than BF% for classifying the studied metabolic disorders. International BF% cutoffs had very low specificity and thus produced a high rate of false positives in both sexes.

Prevalence and predictors of alanine aminotransferase elevation among normal weight, overweight and obese youth in Mexico.

This study aimed to determine the prevalence of and risk factors associated with elevated alanine aminotransferase (ALT) levels among a sample of normal weight, overweight and obese youth from two urban populations in Central Mexico.

Relative validity of a food frequency questionnaire to identify dietary patterns in an adult Mexican population

Objective: To examine the validity of a semi-quantitative food frequency questionnaire (SFFQ) to identify dietary patterns in an adult Mexican population. Materials and methods: A 140-item SFFQ and two 24-hour dietary recalls (24DRs) were administered. Foods were categorized into 29 food groups used to derive dietary patterns via factor analysis. Pearson and intraclass correlations coefficients between dietary pattern scores identified from the SFFQ and 24DRs were assessed. Results: Pattern 1 was high in snacks, fast food, soft drinks, processed meats and refined grains; pattern 2 was high in fresh vegetables, fresh fruits, and dairy products; and pattern 3 was high in legumes, eggs, sweetened foods and sugars. Pearson correlation coefficients between the SFFQ and the 24DRs for these patterns were 0.66 (P<0.001), 0.41 (P<0.001) and 0.29 (P=0.193) respectively. Conclusions: Our data indicate reasonable validity of the SFFQ, using factor analysis, to derive major dietary patterns in comparison with two 24DR.