Andrés Díaz-López

Effect of the glycemic index of the diet on weight loss, modulation of satiety, inflammation, and other metabolic risk factors: a randomized controlled trial

BACKGROUND Low-glycemic index (GI) diets have been proven to have beneficial effects in such chronic conditions as type 2 diabetes, ischemic heart disease, and some types of cancer, but the effect of low-GI diets on weight loss, satiety, and inflammation is still controversial. OBJECTIVE We assessed the efficacy of 2 moderate-carbohydrate diets and a low-fat diet with different GIs on weight loss and the modulation of satiety, inflammation, and other metabolic risk markers. DESIGN The GLYNDIET study is a 6-mo randomized, parallel, controlled clinical trial conducted in 122 overweight and obese adults. Participants were randomly assigned to one of the following 3 isocaloric energy-restricted diets for 6 mo: 1) a moderate-carbohydrate and high-GI diet (HGI), 2) a moderate-carbohydrate and low-GI diet (LGI), and 3) a low-fat and high-GI diet (LF). RESULTS At weeks 16 and 20 and the end of the intervention, changes in body mass index (BMI; in kg/m(2)) differed significantly between intervention groups. Reductions in BMI were greater in the LGI group than in the LF group, whereas in the HGI group, reductions in BMI did not differ significantly from those in the other 2 groups (LGI: -2.45 ± 0.27; HGI: -2.30 ± 0.27; LF: -1.43 ± 0.27; F = 4.616, P = 0.012; pairwise comparisons: LGI compared with HGI, P = 1.000; LGI compared with LF, P = 0.016; HGI compared with LF, P = 0.061). The decrease in fasting insulin, homeostatic model assessment of insulin resistance, and homeostatic model assessment of β cell function was also significantly greater in the LGI group than in the LF group (P < 0.05). Despite this tendency for a greater improvement with a low-GI diet, the 3 intervention groups were not observed to have different effects on hunger, satiety, lipid profiles, or other inflammatory and metabolic risk markers. CONCLUSION A low-GI and energy-restricted diet containing moderate amounts of carbohydrates may be more effective than a high-GI and low-fat diet at reducing body weight and controlling glucose and insulin metabolism. This trial was registered at Current Controlled Trials (www.controlled-trials.com) as ISRCTN54971867.

Consumption of Yogurt, Low-Fat Milk, and Other Low-Fat Dairy Products Is Associated with Lower Risk of Metabolic Syndrome Incidence in an Elderly Mediterranean Population

BACKGROUND The association between consumption of dairy products and the risk of developing metabolic syndrome (MetS) is unclear. OBJECTIVE The purpose of this study was to evaluate the associations between consumption of dairy products (total and different subtypes) and incident MetS in a Mediterranean population at high cardiovascular disease risk. METHODS We prospectively analyzed 1868 men and women (55-80 y old) without MetS at baseline, recruited from different PREDIMED (Prevención con Dieta Mediterránea) centers between October 2003 and June 2009 and followed up until December 2010. MetS was defined according to updated, harmonized criteria. At baseline and yearly thereafter, we determined anthropometric variables, dietary habits by a 137-item validated food-frequency questionnaire, and blood biochemistry. Multivariable-adjusted HRs of MetS or its components were estimated for each of the 2 upper tertiles (vs. the lowest one) of mean consumption of dairy products during the follow-up. RESULTS During a median follow-up of 3.2 y, we documented 930 incident MetS cases. In the multivariable-adjusted model, HRs (95% CIs) of MetS for the comparison of extreme tertiles of dairy product consumption were 0.72 (0.61, 0.86) for low-fat dairy, 0.73 (0.62, 0.86) for low-fat yogurt, 0.78 (0.66, 0.92) for whole-fat yogurt, and 0.80 (0.67, 0.95) for low-fat milk. The respective HR for cheese was 1.31 (1.10, 1.56). CONCLUSIONS Higher consumption of low-fat dairy products, yogurt (total, low-fat, and whole-fat yogurt) and low-fat milk was associated with a reduced risk of MetS in individuals at high cardiovascular disease risk from a Mediterranean population. Conversely, higher consumption of cheese was related to a higher risk of MetS. This trial was registered at controlled-trials.com as ISRCTN35739639.

Reduced serum concentrations of carboxylated and undercarboxylated osteocalcin are associated with risk of developing type 2 diabetes mellitus in a high cardiovascular risk population: a nested case-control study.

CONTEXT AND OBJECTIVE Because it has been suggested that osteocalcin (OC), an osteoblast-derived hormone, is a new link between bone and glucose metabolism, we tested whether serum carboxylated osteocalcin (cOC) and undercarboxylated osteocalcin (ucOC) levels are independently associated with the development of type 2 diabetes in subjects at high cardiovascular risk. DESIGN, SETTING, AND PARTICIPANTS A prospective, nested case-control study was conducted using data from the Prevención con Dieta Mediterránea (PREDIMED) study. We included 153 case subjects with newly diagnosed diabetes and 306 individually matched control subjects free of diabetes identified during a mean 5-year follow-up. Conditional logistic regression models were used to estimate matched odds ratios for incident diabetes according to categories of both forms of OC measured by ELISAs. RESULTS Baseline serum concentrations of both forms of OC were significantly lower in case subjects than in control subjects. In subjects with incident cases of diabetes, concentrations of cOC, but not of ucOC, were inversely and significantly associated with homeostasis model assessment of insulin resistance levels (β = -0.335) and with fasting glucose concentrations (β = -0.044) in control subjects, independent of other relevant confounders. In the conditional logistic model that took into account the matching factors, the odds ratios for diabetes incidence in the lowest vs the highest tertile of cOC and ucOC were 2.03 (95% confidence interval, 1.32-3.13) and 1.88 (1.23-2.85), respectively. Further adjustment for family history of diabetes, lifestyle, and other confounding factors did not appreciably change the magnitude of these associations. CONCLUSION In a population at high cardiovascular risk, low concentrations of serum cOC and ucOC were strongly associated with an increased risk of incident diabetes.

Waist-to-Height Ratio and Cardiovascular Risk Factors in Elderly Individuals at High Cardiovascular Risk

Introduction Several anthropometric measurements have been associated with cardiovascular disease, type-2 diabetes mellitus and other cardiovascular risk conditions, such as hypertension or metabolic syndrome. Waist-to-height-ratio has been proposed as a useful tool for assessing abdominal obesity, correcting other measurements for the height of the individual. We compared the ability of several anthropometric measurements to predict the presence of type-2 diabetes, hyperglycemia, hypertension, atherogenic dyslipidemia or metabolic syndrome. Materials and Methods In our cross-sectional analyses we included 7447 Spanish individuals at high cardiovascular risk, men aged 55–80 years and women aged 60–80 years, from the PREDIMED study. Logistic regression models were fitted to evaluate the odds ratio of presenting each cardiovascular risk factor according to various anthropometric measures. The areas under the receiver-operating characteristic curve (AUC) were used to compare the predictive ability of these measurements. Results In this relatively homogeneous cohort with 48.6% of type-2 diabetic individuals, the great majority of the studied anthropometric parameters were significantly and positively associated with the cardiovascular risk factors. No association was found between BMI and body weight and diabetes mellitus. The AUCs for the waist-to-height ratio and waist circumference were significantly higher than the AUCs for BMI or weight for type-2 diabetes, hyperglycemia, atherogenic dyslipidemia and metabolic syndrome. Conversely, BMI was the strongest predictor of hypertension. Conclusions We concluded that measures of abdominal obesity showed higher discriminative ability for diabetes mellitus, high fasting plasma glucose, atherogenic dyslipidemia and metabolic syndrome than BMI or weight in a large cohort of elderly Mediterranean individuals at high cardiovascular risk. No significant differences were found between the predictive abilities of waist-to-height ratio and waist circumference on the metabolic disease.

Lifestyle recommendations for the prevention and management of metabolic syndrome: an international panel recommendation

The importance of metabolic syndrome (MetS) lies in its associated risk of cardiovascular disease and type 2 diabetes, as well as other harmful conditions such as nonalcoholic fatty liver disease. In this report, the available scientific evidence on the associations between lifestyle changes and MetS and its components is reviewed to derive recommendations for MetS prevention and management. Weight loss through an energy-restricted diet together with increased energy expenditure through physical activity contribute to the prevention and treatment of MetS. A Mediterranean-type diet, with or without energy restriction, is an effective treatment component. This dietary pattern should be built upon an increased intake of unsaturated fat, primarily from olive oil, and emphasize the consumption of legumes, cereals (whole grains), fruits, vegetables, nuts, fish, and low-fat dairy products, as well as moderate consumption of alcohol. Other dietary patterns (Dietary Approaches to Stop Hypertension, new Nordic, and vegetarian diets) have also been proposed as alternatives for preventing MetS. Quitting smoking and reducing intake of sugar-sweetened beverages and meat and meat products are mandatory. Nevertheless, there are inconsistencies and gaps in the evidence, and additional research is needed to define the most appropriate therapies for MetS. In conclusion, a healthy lifestyle is critical to prevent or delay the onset of MetS in susceptible individuals and to prevent cardiovascular disease and type 2 diabetes in those with existing MetS. The recommendations provided in this article should help patients and clinicians understand and implement the most effective approaches for lifestyle change to prevent MetS and improve cardiometabolic health.

Effects of Mediterranean Diets on Kidney Function: A Report From the PREDIMED Trial

BACKGROUND Epidemiologic observations have linked healthy dietary patterns to improved kidney function. STUDY DESIGN We assessed the effects of the Mediterranean diet (MedDiet) on kidney function in both a cross-sectional assessment and after a 1-year intervention in a cohort of the PREDIMED (Prevención con Dieta Mediterránea) Study, a multicenter 3-arm randomized clinical trial to determine the efficacy of the MedDiet on primary cardiovascular prevention. SETTING & PARTICIPANTS Community-dwelling men aged 55-80 years and women aged 60-80 years at high risk of cardiovascular disease from Reus, Spain. INTERVENTION Participants were randomly assigned to 3 ad libitum diets: a MedDiet supplemented with virgin olive oil (MedDiet + olive oil), a MedDiet supplemented with mixed nuts (MedDiet + nuts), or a control low-fat diet. OUTCOMES Estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio (ACR). MEASUREMENTS Nutrient intake, adherence to the MedDiet, lifestyle variables, cardiovascular risk factors, serum urea and creatinine concentrations, eGFR, and urinary ACR were evaluated at baseline and after intervention for 1 year. RESULTS Baseline kidney function markers were similar across quartiles of adherence to the MedDiet in 785 participants (55% women; mean age, 67 years). After a 1-year intervention in 665 participants, the 3 dietary approaches were associated with improved kidney function, with similar average increases in eGFR (4.7 [95% CI, 3.2-6.2], 3.5 [95% CI, 1.9-5.0], and 4.1 [95% CI, 2.8-5.5] mL/min/1.73 m(2) for the MedDiet + olive oil, MedDiet + nuts, and control groups, respectively [P < 0.001 vs baseline for each; P = 0.9 for differences among groups]), but no changes in ACRs after adjustment for various confounders. LIMITATIONS Generalization of results to other age groups or ethnicities. GFR was not directly measured. CONCLUSIONS The results do not support the notion that the MedDiet has a beneficial effect on kidney function over and above that of advice for a low-fat diet in elderly individuals at high cardiovascular risk.

Increased Serum Calcium Levels and Risk of Type 2 Diabetes in Individuals at High Cardiovascular Risk

OBJECTIVE Insulin resistance and secretion depend on calcium homeostasis. Cross-sectional studies have associated elevated serum calcium levels with markers of impaired glucose metabolism. However, only one prospective cohort study has demonstrated an increased risk of diabetes in individuals with increased serum calcium concentrations. The aim of the current study was to prospectively investigate the association between albumin-adjusted serum calcium concentrations and type 2 diabetes in subjects at high cardiovascular risk. RESEARCH DESIGN AND METHODS Prospective assessment of participants from two Spanish PREDIMED study centers where serum calcium levels were measured at baseline and yearly during follow-up. Multivariate-adjusted Cox regression models were fitted to assess associations between baseline and changes during follow-up in serum calcium levels and relative risk of diabetes incidence. RESULTS After a median follow-up of 4.78 years, 77 new cases of type 2 diabetes occurred. An increase in serum calcium levels during follow-up was related to an increased risk of diabetes. In comparison with individuals in the lowest tertile (−0.78 ± 0.29 mg/dL), the hazard ratio (HR) and 95% CI for diabetes incidence in individuals in the higher tertile of change (0.52 ± 0.13 mg/dL) during follow-up was 3.48 (95% CI 1.48–8.17; P for trend = 0.01). When albumin-adjusted serum calcium was analyzed as a continuous variable, per 1 mg/dL increase, the HR of diabetes incidence was 2.87 (95% CI 1.18–6.96; P value = 0.02). These associations remained significant after individuals taking calcium supplements or having calcium levels out of normal range had been excluded. CONCLUSIONS An increase in serum calcium concentrations is associated with an increased risk of type 2 diabetes in individuals at high cardiovascular risk.

Dietary Marine ω-3 Fatty Acids and Incident Sight-Threatening Retinopathy in Middle-Aged and Older Individuals With Type 2 Diabetes: Prospective Investigation From the PREDIMED Trial

Importance Diabetic retinopathy (DR) is a devastating complication of individuals with type 2 diabetes mellitus. The retina is rich in long-chain ω-3 polyunsaturated fatty acids (LCω3PUFAs), which are substrate for oxylipins with anti-inflammatory and antiangiogenic properties. Experimental models support dietary LCω3PUFA protection against DR, but clinical data are lacking. Objective To determine whether LCω3PUFA intake relates to a decreased incidence of sight-threatening DR in individuals with type 2 diabetes older than 55 years. Design, Setting, and Participants In late 2015, we conceived a prospective study within the randomized clinical trial Prevención con Dieta Mediterránea (PREDIMED), testing Mediterranean diets supplemented with extra virgin olive oil or nuts vs a control diet for primary cardiovascular prevention. The trial was conducted in primary health care centers in Spain. From 2003 to 2009, 3614 individuals aged 55 to 80 years with a previous diagnosis of type 2 diabetes were recruited. Full data were available for 3482 participants (48% men; mean age 67 years). Exposures Meeting the dietary LCω3PUFA recommendation of at least 500 mg/d for primary cardiovascular prevention, as assessed by a validated food-frequency questionnaire. Main Outcomes and Measures The main outcome was incident DR requiring laser photocoagulation, vitrectomy, and/or antiangiogenic therapy confirmed by an external adjudication committee. Results Of the 3482 participants, 48% were men and the mean age was 67 years. A total of 2611 participants (75%) met target LCω3PUFA recommendation. During a median follow-up of 6 years, we documented 69 new events. After adjusting for age, sex, intervention group, and lifestyle and clinical variables, participants meeting the LCω3PUFA recommendation at baseline (≥500 mg/d) compared with those not fulfilling this recommendation (<500 mg/d) showed a 48% relatively reduced risk of incident sight-threatening DR, with a hazard ratio of 0.52 (95% CI, 0.31-0.88; P = .001). This association was slightly stronger for yearly updated LCω3PUFA intake (relative risk, 0.48; 95% CI, 0.28-0.82; P = .007). Conclusions and Relevance In middle-aged and older individuals with type 2 diabetes, intake of at least 500 mg/d of dietary LCω3PUFA, easily achievable with 2 weekly servings of oily fish, is associated with a decreased risk of sight-threatening DR. Our results concur with findings from experimental models and the current model of DR pathogenesis. Trial Registration clinicaltrials.gov Identifier: http://www.controlled-trials.com/ISRCTN35739639.

Cross-sectional associations between macronutrient intake and chronic kidney disease in a population at high cardiovascular risk

BACKGROUND & AIMS The aim was to examine the associations between macronutrient intake and the prevalence of chronic kidney disease (CKD) or microalbuminuria (MiA) in individuals at high cardiovascular risk. METHODS Cross-sectional analyses conducted in 2123 nondiabetic individuals from the PREDIMED study. Dietary data were collected using a food-frequency questionnaire. Analysis of covariance was used to assess associations between quartiles of nutrient intake and estimated glomerular filtration rate (eGFR) or urinary albumin-to-creatinine ratio (ACR). The odds ratio (OR) for the presence of CKD or MiA according to quartiles of nutrient intake was assessed by logistic regression models. RESULTS Individuals in the highest quartile of n-6 polyunsaturated fatty acid (PUFA) intake showed lower average eGFR. Individuals in the top quartile of fiber intake had a decreased risk of CKD [OR: 0.68; 95% CI: 0.48-0.95]. Conversely, subjects in the highest quartile of n-6 PUFA intake showed an increased risk of CKD [OR: 1.44; 95% CI: 1.03-2.01]. No significant associations were found between the intake of other macronutrients and eGFR, urinary ACR or risk of CKD or MiA. CONCLUSIONS A high fiber intake was associated with a decreased risk of CKD, while a high n-6 PUFA intake was inversely associated with eGFR and directly associated with an increased risk of CKD.

Leisure-time physical activity, sedentary behaviors, sleep, and cardiometabolic risk factors at baseline in the PREDIMED-PLUS intervention trial: A cross-sectional analysis

Limited data exists on the interrelationships between physical activity (PA), sedentary behaviors and sleep concerning cardiometabolic risk factors in aged adults at high cardiovascular disease risk. Our aim was to examine independent and joint associations between time spent in leisure-time PA, sedentary behaviors and sleep on the prevalence of obesity, type 2 diabetes (T2D) and components of the metabolic syndrome (MetS) in Mediterranean individuals at high cardiovascular risk. Cross-sectional analyses were performed on baseline data from 5776 Spanish adults (aged 55-75y in men; 60-75y in women) with overweight/obesity and MetS, from October 2013 to October 2016, in the PREDIMED-PLUS trial. Employing multivariable-adjusted Cox regression with robust variance and constant time (given the cross-sectional design), higher prevalence of obesity, T2D and abdominal obesity as component of the MetS were associated with greater time in TV-viewing (Relative Risk, RR: 1.02, 95%CI: 1.01, 1.03; RR:1.04, 95%CI: 1.02, 1.06 and RR: 1.01 95%CI: 1.00, 1.02; respectively, all P < .01). Conversely, greater time in moderate-vigorous PA (MVPA) was associated with lower prevalence of obesity, T2D, abdominal obesity and low HDL-cholesterol (RR: 0.95, 95%CI: 0.93, 0.97; RR: 0.94, 95%CI: 0.89, 0.99; RR: 0.97, 95%CI: 0.96, 0.98; and RR: 0.95, 95%CI: 0.91, 0.99, respectively, all P < .05). For these outcomes, theoretically substituting 1-h/day of MVPA for 1-h/day TV-viewing was also significantly associated with lower prevalence (RR 0.91 to 0.97, all P < .05). Similar lower RR in these outcomes was observed when substituting 1-h/day of MVPA for 1-h/day of sleeping. Longer time watching TV and not meeting MVPA recommendations were jointly associated with higher RR of the prevalence of obesity and T2D. We concluded that, in senior individuals at high cardiovascular risk, greater time spent on MVPA and fewer on sedentary behaviors was inversely associated with prevalence of obesity, T2D, and some of the components of MetS.