Reduction of circulating methylglyoxal levels by a Mediterranean diet is associated with preserved kidney function in patients with type 2 diabetes and coronary heart disease: From the CORDIOPREV randomized controlled trial.

AIM: Advanced glycation end products (AGEs) play a role in kidney disease in type 2 diabetes mellitus (T2DM). However, there have been no prior controlled clinical trials examining the effects of specific diets on AGE metabolism and their impact on kidney function. Our aim was to assess whether modulating AGE metabolism resulting in reduced AGEs levels, after consumption of two healthy diets, could delay kidney function decline in patients with T2DM and coronary heart disease (CHD). METHODS: T2DM patients (540 out of 1002 patients from the CORDIOPREV study), with estimated glomerular filtration rate (eGFR) ≥ 30 ml/min/1.73 m2, were classified based on their baseline kidney function: normal eGFR (≥ 90 ml/min/1.73 m2), mildly decreased eGFR (60- < 90 ml/min/1.73 m2) and moderately decreased eGFR (<60 ml/min/1.73 m2). Serum AGE levels, methylglyoxal (MG) and N-carboximethyllysine (CML), and gene expression related to AGE metabolism (AGER1, RAGE, and GloxI mRNA) were measured before and after 5-years of dietary intervention (a Mediterranean diet or a low-fat diet). RESULTS: Mediterranean diet produced a lower declined of eGFR compared to the low-fat diet only in patients with mildly decreased eGFR (P = 0.035). Moreover, Mediterranean diet was able to decrease MG levels and increase GloxI expression in normal and mildly decreased eGFR patients (all P < 0.05). One standard deviation increment of MG levels after dietary intervention resulted in a 6.8-fold (95 % CI 0.039;0.554) higher probability of eGFR decline. CONCLUSION: Our study showed that lowering circulating AGE levels, specifically MG, after following a Mediterranean diet, might be linked to the preservation of kidney function, evidenced by a decreased decline of eGFR in T2DM patients with CHD. Patients with mildly decreased eGFR could potentially benefit more from AGE reduction in maintaining kidney function.

Long-term consumption of a mediterranean diet or a low-fat diet on kidney function in coronary heart disease patients: The CORDIOPREV randomized controlled trial.

BACKGROUND & AIMS: Lifestyle and dietary habits influence kidney function, playing an important role in the prevention and development of chronic kidney disease (CKD). The effectiveness of the Mediterranean diet in preserving kidney function has been seen in primary prevention. However, no scientific evidence is currently available to determine which dietary pattern is more effective in the management of CKD in secondary cardiovascular disease prevention. Thus, our aim was to evaluate the efficacy of the long-term consumption of two healthy dietary patterns (a Mediterranean diet rich in extra-virgin olive oil (EVOO) compared to a low-fat diet rich in complex carbohydrates) in preserving kidney function in coronary heart disease (CHD) patients. METHODS: CHD patients (n = 1002) from the CORDIOPREV study were randomized to follow a Mediterranean diet (35% fat, 22% MUFA, <50% carbohydrates) or a low-fat diet (28% fat, 12% MUFA, >55% carbohydrates). Kidney function was assessed by the determination of serum creatinine-based estimated glomerular filtration rate (eGFR) at baseline and after 5-years of dietary intervention. Patients were classified according to their type 2 diabetes (T2DM) status, using baseline eGFR (normal eGFR: ≥ 90 mL/min/1.73 m2; mildly-impaired eGFR: 60 to <90 mL/min/1.73 m2, severely-impaired eGFR: <60 mL/min/1.73 m2) to evaluate its influence on the progression of kidney function. Multiple linear regression analysis were performed to determine the contribution of different clinical and anthropometric parameters to changes in eGFR. RESULTS: Although eGFR declined after both dietary interventions compared to baseline (all p < 0.001), the Mediterranean diet produced a lower decline of eGFR compared to the low-fat diet in patients with T2DM (p = 0.040). This effect was also observed when the overall population was considered (p = 0.033). No significant differences were observed in eGFR between the two diets in non-T2DM patients. In addition, this differential effect of the Mediterranean diet was mainly observed in patients with mildly-impaired eGFR in which this diet slowed eGFR progression (p = 0.002). CONCLUSIONS: The long-term consumption of a Mediterranean diet rich in EVOO, when compared to a low-fat diet, may preserve kidney function, as shown by a reduced decline in eGFR in CHD patients with T2DM. Patients with mildly-impaired eGFR may benefit more from the beneficial effect of the consumption of the Mediterranean diet in preserving kidney function. These findings reinforce the clinical benefits of the Mediterranean diet in the context of secondary cardiovascular disease prevention. CLINICAL TRIAL REGISTRATION: URL, http://www.cordioprev.es/index.php/en. Clinicaltrials.gov number, NCT00924937.

Diabetes Remission Is Modulated by Branched Chain Amino Acids According to the Diet Consumed: From the CORDIOPREV Study.

SCOPE: Branched Chain Amino Acids (BCAA) plasma levels may be differentially associated with type 2 diabetes mellitus (T2DM) remission through the consumption of the Mediterranean diet (Med) and a low-fat (LF) diet. METHODS: One hundred eighty-three newly diagnosed T2DM patients within the CORDIOPREV study are randomized to consume the Med or a LF diet. BCAA plasma levels (isoleucine, leucine, and valine) are measured at fasting and after 120 min of an oral glucose tolerance test (OGTT) at the baseline of the study and after 5 years of the dietary intervention. RESULTS: Isoleucine, leucine, and valine plasma levels after 120 min of an OGTT in the Med diet (N = 80) are associated by COX analysis with T2DM remission: HR per SD (95% CI): 0.53 (0.37-0.77), 0.75 (0.52-1.08), and 0.61 (0.45-0.82), respectively; no association is found in patients who consumed a LF diet (N = 103). BCAA plasma levels combined in a score show a HR of 3.33 (1.55-7.19) of T2DM remission for patients with a high score values in the Med diet, while in those with a LF diet, no association is found. CONCLUSION: The study suggests that BCAA measurements potentially be used as a tool to select the most suitable diet to induce T2DM remission by nutritional strategies.

Beta cell functionality and hepatic insulin resistance are major contributors to type 2 diabetes remission and starting pharmacological therapy: from CORDIOPREV randomized controlled trial.

In order to assess whether previous hepatic IR (Hepatic-IRfasting) and beta-cell functionality could modulate type 2 diabetes remission and the need for starting glucose-lowering treatment, newly-diagnosed type 2 diabetes participants who had never received glucose-lowering treatment (190 out of 1002) from the CORonary Diet Intervention with Olive oil and cardiovascular PREVention study (a prospective, randomized and controlled clinical trial), were randomized to consume a Mediterranean or a low-fat diet. Type 2 diabetes remission was defined according to the American Diabetes Association recommendation for levels of HbA1c, fasting plasma glucose and 2h plasma glucose after oral glucose tolerance test, and having maintained them for at least 2 consecutive years. Patients were classified according to the median of Hepatic-IRfasting and beta-cell functionality, measured as the disposition index (DI) at baseline. Cox proportional hazards regression determined the potential for Hepatic-IRfasting and DI indexes as predictors of diabetes remission and the probability of starting pharmacological treatment after a 5-year follow-up. Low-Hepatic-IRfasting or high-DI patients had a higher probability of diabetes remission than high-Hepatic-IRfasting or low-DI subjects (HR:1.79; 95% CI 1.06-3.05; and HR:2.66; 95% CI 1.60-4.43, respectively) after a dietary intervention with no pharmacological treatment and no weight loss. The combination of low-Hepatic-IRfasting and high-DI presented the highest probability of remission (HR:4.63; 95% CI 2.00-10.70). Among patients maintaining diabetes, those with high- Hepatic-IRfasting and low-DI showed the highest risk of starting glucose-lowering therapy (HR:3.24;95% CI 1.50-7.02). Newly-diagnosed type 2 diabetes patients with better beta-cell functionality and lower Hepatic-IRfasting had a higher probability of type 2 diabetes remission in a dietary intervention without pharmacological treatment or weight loss, whereas among patients not achieving remission, those with worse beta-cell functionality and higher Hepatic-IRfasting index had the highest risk of starting glucose-lowering treatment after 5 years of follow-up.