Dietary protein sources and risk of diabetic nephropathy in women: A case-control study

Mediterranean diet and diabetic microvascular complications: a systematic review and meta-analysis

BACKGROUND

Diabetic microvascular complications, including diabetic retinopathy (DR), diabetic nephropathy (DN), and diabetic peripheral neuropathy (DPN), contribute significantly to morbidity and healthcare burdens among individuals with diabetes. The Mediterranean diet (MD) has been associated with improved metabolic health, but its role in mitigating microvascular complications remains unclear. This systematic review and meta-analysis aimed to assess the impact of MD adherence on the risk and progression of these complications.

METHODS

A comprehensive search of PubMed, Web of Science, Embase, and Scopus was conducted through February 12, 2025 to identify studies evaluating MD adherence and diabetic microvascular complications. Meta-analysis was performed where possible, with effect sizes reported as odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

Fourteen studies, encompassing 138 to 71,392 participants, were included. Meta-analysis indicated a significant reduction in DR risk among individuals adhering to the MD (HR: 0.69, 95% CI: 0.49-0.97, p = 0.03; OR: 0.32, 95% CI: 0.12-0.82, p = 0.02). A lower likelihood of DN development was observed (HR: 0.85, 95% CI: 0.73-0.99, p = 0.04; OR: 0.49, 95% CI: 0.25-0.96, p = 0.04). However, results for diabetic neuropathy were inconclusive due to study heterogeneity. Sensitivity analyses revealed notable heterogeneity and publication bias was detected in some analyses.

CONCLUSION

Adherence to the Mediterranean diet is associated with a reduced risk of diabetic nephropathy and retinopathy, supporting its potential as a dietary intervention for diabetes management. However, the evidence for neuropathy remains inconclusive. Future well-controlled randomized trials are needed to strengthen causal inferences and refine clinical recommendations for MD-based interventions in diabetic microvascular complications.

Nutritional Approach to Diabetic Sarcopenia: A Comprehensive Review

PURPOSE OF THE REVIEW

The aim of this review is to discuss and evaluate diabetic sarcopenia (DS) and its relationship with nutrition by discussing the mechanisms of diabetic sarcopenia in detail and comprehensively reviewing the literature.

RECENT FINDINGS

Type 2 diabetes (T2DM) affects approximately 25% of people aged 50 years and over and indicates a significant the cost of health for the elderly. Nutrition is an important part of these treatment approaches, and in this review, the literature was comprehensively reviewed, focusing on understanding the mechanisms of DS and discussing its relationship with nutrition. A comprehensive search was conducted on Web of Science, Google Scholar, Scopus, Science Direct, and PubMed from inception up to July 2024. The aim of nutritional treatment for DS is to improve muscle mass, muscle strength and physical performance while improving diabetes-related metabolic risk and glucose levels. In this context, it is important to determine energy intake in individuals with DS according to calorie intake exceeding 30 kcal/kg. For these individuals, a protein intake of at least 1-1.2 g/kg/day is recommended, with an emphasis on the number and timing of meals and a nutritional pattern rich in branched chain amino acids (BCAA). In addition, it is important to adopt a diet rich in antioxidants and to choose diet patterns that contain sufficient levels of macro and micronutrients. The Mediterranean diet model can be a good diet option for individuals with DS. Comprehensive studies in this field are needed so that clinicians can make specific dietary recommendations for DS.

Adherence of Plant-Based Dietary Index in Odds of Diabetic Nephropathy in Women: A Case-Control Study

BACKGROUND & AIMS

Recent research has suggested that adherence to plant-based dietary index (PDI) may reduce the risk of type 2 diabetes and related complications like diabetic nephropathy (DN). Therefore, the aim of this study was to investigate the possible association of PDI with the odds of DN.

METHODS

We enrolled 105 eligible women with DN and 105 controls without DN (30-65 years). A 147-item food frequency questionnaire was used to evaluate an overall PDI, healthy plant-based dietary index (hPDI), and unhealthful PDI. Biochemical variables and anthropometric measurements were assessed for all patients using predefined protocols.

RESULTS

According to our final analyses, after controlling for potential confounders, participants with greater adherence to overall PDI (OR: 0.29; 95% CI: 0.15-0.56; P < .001) and hPDI (OR: 0.30; 95% CI: 0.15-0.56; P < .001) had 71% and 70% lower odds of DN compared to those with a low adherence, respectively. Conversely, subjects with a higher adherence to the unhealthful PDI had a positive association with increased odds of DN in the crude (OR = 5.00; 95% CI = 2.78-8.98; P < .001) and adjusted models (OR = 4.27; 95% CI = 2.24-8.14; P < .001), respectively.

CONCLUSION

The results of this study showed that greater adherence to overall PDI and hPDI was inversely associated with the odds of DN. However, further prospective studies are warranted to confirm these results.

Nutritional Strategies against Diabetic Nephropathy: Insights from Animal Studies and Human Trials

Diabetic nephropathy (DN), defined as continuously elevated urinary albumin and a diminished estimated glomerular filtration rate, is a serious complication of both type 1 diabetes and type 2 diabetes and is the main cause of end-stage kidney disease. Patients with end-stage renal disease require chronic kidney dialysis and/or a kidney transplantation. Research highlights the role of diet in modulating specific signaling pathways that are instrumental in the progression of DN. Nutrient-sensitive pathways, affected by nutritional compounds and dietary components, offer a novel perspective on the management of DN by influencing inflammation, oxidative stress, and nutrient metabolism. Animal models have identified signaling pathways related to glucose metabolism, inflammation responses, autophagy, and lipid metabolism, while human population studies have contributed to the clinical significance of designing medical and nutritional therapies to attenuate DN progression. Here, we will update recent progress in research into the renoprotective or therapeutic effects of nutritional compounds, and potential nutrition-modulated pathways.

The association between dietary micronutrient patterns and odds of diabetic nephropathy: A case-control study

Uncontrolled diabetes can lead to diabetic nephropathy (DN). The aim of the study was to investigate the relationship between different dietary micronutrient patterns and risk of DN in women. This was a case-control study. One hundred and five patients had DN (defined as urinary mg of albumin per gram of creatinine ≥30 mg/g) were chosen as the case and 105 women without DN were chosen as control. Dietary intakes were assessed by a semi-quantitative food frequency questionnaire. Principal component analysis with varimax rotation was used to derive the micronutrient patterns. Patterns were divided into two groups of lower and higher than median. Logistic regression was used to discern and find the odds ratio (ORs) of DN, and its 95% confidence interval (CI) based on the micronutrient patterns in crude and adjusted model. Three patterns which were included, (1) mineral patterns such as chromium, manganese, biotin, vitamin B6, phosphorus, magnesium, selenium, copper, zinc, potassium, and iron, (2) water-soluble vitamin patterns such as vitamin B5, B2, folate, B1, B3, B12, sodium and C, and (3) fat-soluble vitamin patterns such as calcium, vitamin K, beta carotene, alpha tocopherol, alpha carotene, vitamin E, and vitamin A, were extracted. An inverse relationship was found between risk of DN and following mineral patterns and fat-soluble vitamin patterns in adjusted model (ORs = 0.51 [95% CI 0.28-0.95], p = .03) and (ORs = 0.53 [95% CI 0.29-0.98], p = .04), respectively. No relationship was seen between water-soluble vitamin patterns and risk of DN in crude and adjusted model but the significance was decreased in adjusted model. The risk of DN was 47% decreased after high adherence of fat-soluble vitamin patterns. In addition, we saw a 49% decrease of risk of DN in high adherence group of mineral patterns. The findings confirm that renal-protective dietary patterns can reduce risk of DN.

Diet, exercise, and pharmacotherapy for sarcopenia in people with diabetes

Diabetes prevalence is increasing rapidly in older people, and sarcopenia is prevalent as a novel complication, particularly in patients with type 2 diabetes mellitus (T2DM). Therefore, sarcopenia prevention and treatment in these people is necessary. Diabetes accelerates sarcopenia through several mechanisms, such as hyperglycemia, chronic inflammation and oxidative stress. The effects of diet, exercise, and pharmacotherapy on sarcopenia in patients with T2DM need to be considered. In diet, low intake of energy, protein, vitamin D, and ω-3 fatty acid are associated with sarcopenia risk. In exercises, although intervention studies in people, especially older and non-obese patients with diabetes, are few, accumulating evidence shows the usefulness of exercise, particularly resistance exercise for muscle mass and strength, and aerobic exercise for physical performance in sarcopenia. In pharmacotherapy, certain classes of anti-diabetes compounds have possibility of preventing sarcopenia. However, much data on diet, exercise, and pharmacotherapy were obtained in obese and non-elderly patients with T2DM, demanding actual clinical data on non-obese and older patients with diabetes.

Prevalence and association of diabetic nephropathy in newly diagnosed Chinese patients with diabetes in the Hebei province: A single-center case-control study

Diabetes is a chronic disease and has huge pressure on patients and the medical system, especially for patients with diabetic complications, for example, diabetic nephropathy. Diabetic nephropathy is a diabetic complication associated with damage to the kidney. To improve the quality of life of patients with diabetes, it is necessary to understand the factors that are associated with diabetic nephropathy. The objective of the study was to find the prevalence of diabetic nephropathy in newly diagnosed patients with diabetes and to develop the association between clinicopathological parameters and diabetic nephropathy. In a case-control study, demographics, anthropometric, and clinicopathological parameters of a total of 305 newly diagnosed patients with diabetes (the fasting blood glucose ≥ 7.0 mM/L and/or glycosylated hemoglobin ≥ 6.5 mM/L) in Hebei province were included in the analysis. If the urine albumin to creatinine ratio was ≥ 30 (microalbuminuria) then patients were considered diabetic nephropathy. Among enrolled patients, 206 (68%) were males and 99 (32%) were females and they were 46 to 71 years old. Demographic variables and health-related behaviors were the same among patients with diabetes either with nephropathy (case group, n = 135) or patients without nephropathy (control group, n = 170, P > .05 for all). The prevalence of diabetic nephropathy was 44%. Female to male ratio was 1:1.7 in the case group. Patients with diabetic nephropathy had higher body weight (P < .0001), waist circumference (P = .0006), and body mass index (P = .0002) than those of patients without nephropathy. Abnormal urinary globulin (P = .041, odd ratio (OR): 1.1231) was associated with diabetic nephropathy. Aspartate transaminase (P = .0651, OR: 0.8541), alkaline phosphatase (P = .0661, OR: 0.8122), hypertension (P = .0821, OR: 0.8214), and blood urea nitrogen (P = .0842, OR: 0.9411) were not significantly associated with diabetic neuropathy. However, they are near the statistical cutoff value. The prevalence of diabetic nephropathy in newly diagnosed diabetic patients of Hebei province is higher than those of the other provinces. Urinary globulin excretion had a weak association with the presence of nephropathy defined by urinary albumin excretion in patients with diabetes. The presence of other diabetic complications is also an essential parameter for diabetic nephropathy. Males are more susceptible to diabetic nephropathy than females if diabetic (Evidence Level: V; Technical Efficacy: Stage 3).

Does the Mediterranean diet reduce the odds of diabetic nephropathy in women? A case–control study

Background

In recent decades, the prevalence of chronic diseases such as diabetes is increasing. One of the major complications of diabetes is diabetic nephropathy (DN), so it is important to find a way that can delay or control the onset of DN. Therefore, in this study, we investigated the relationship between the Mediterranean diet (MED) and the odds of DN.

Methods

This case–control study was performed among 210 women (30–65 years) who were referred to the Kowsar Diabetes Clinic in Semnan, Iran. Biochemical variables and anthropometric measurements were assessed. The food frequency questionnaire (FFQ) was used to calculate dietary intakes. Data from dietary intakes based on the FFQ were used to evaluate the MED score. Logistic regression was used to examine the associations.

Results

Our results showed that in the crude model with higher adherence to the MED (OR: 0.272; 95% CI: 0.154, 0.481; P = 0.001), the odds of DN has reduced by 73%, and in model 1, after controlling for potential confounders, with higher adherence to the MED (OR: 0.239; 95% CI: 0.128, 0.447; P = 0.001), the odds of DN has reduced by 76% compared to low adherence. Also, in model 1, significant associations were observed between high consumption of grains (OR: 0.360; 95% CI: 0.191, 0.676; P = 0.001), legumes (OR: 0.156; 95% CI: 0.083, 0.292; P = 0.001), vegetables (OR: 0.273; 95% CI: 0.149, 0.501; P = 0.001), fruits (OR: 0.179; 95% CI: 0.093, 0.347; P = 0.001), fish (OR: 0.459; 95% CI: 0.254, 0.827; P = 0.01), and reduced odds of DN (P &lt; 0.05).

Conclusion

We observed that with higher adherence to the MED, the odds of DN had reduced through mechanisms. However, additional studies are needed to confirm these findings.

Association of Dietary Fish and n-3 Unsaturated Fatty Acid Consumption with Diabetic Nephropathy from a District Hospital in Northern Taiwan

Nephropathy caused by diabetes mellitus (DM) is the main cause of end-stage renal disease (ESRD). To understand the association of dietary intake with renal function indicators among patients with diabetic nephropathy (DN), this cross-sectional study was conducted at the dietetic consultation clinic of the Taoyuan Armed Forces General Hospital in Taiwan. In total, 317 participants were recruited for this study. Patients with diabetes who had a urinary albumin-creatinine ratio (UACR) of ≥30 mg/g were defined as having DN. The anthropometric characteristics, blood biochemistry, and renal function of the participants were assessed. Furthermore, a semiquantitative food frequency questionnaire (SQFFQ) was administered to investigate the dietary intake of the participants in the DM and DN groups. The result showed that participants in the DN group were older, had longer diabetes duration and poorer glycemic control and renal function than those in the DM group. Logistic regression models revealed that intake of high-fat marine fishes had the lowest odds ratio (OR) for DN risk compared with other fishes (OR: 0.868; 95% CI: 0.781-0.965, p = 0.009). Shellfish, soybean products, and skim milk also provided better protective effects to decrease the risk of DN. A further analysis of polyunsaturated fatty acids revealed that Σn-3 PUFAs significantly reduced DN risk, while Σn-6 PUFAs did not, especially EPA (OR: 0.821; 95% CI: 0.688-0.979, p = 0.029) and DHA (OR: 0.903; 95% CI: 0.823-0.992, p = 0.033) regardless of whether the variables were adjusted, including diabetes duration, age, and HbA1c. Our findings suggest that a diet that incorporates high-fat fish, shellfish, soybean products, and a lower Σn-6/Σn-3 ratio can mitigate DN risk.

What we know about protein gut metabolites: Implications and insights for human health and diseases

Gut microbiota is a complex ecosystem of symbiotic bacteria that contribute to human metabolism and supply intestinal metabolites, whose production is mainly influenced by the diet. Dietary patterns characterized by a high intake of protein promotes the growth of proteolytic bacteria's, which produce metabolites from undigested protein fermentation. Microbioal protein metabolites can regulate immune, metabolic and neuronal responses in different target organs. Metabolic pathways of these compounds and their mechanisms of action on different pathologies can lead to the discovery of new diagnostic techniques, drugs and the potential use as functional ingredients in food. This review discusses the potential mechanisms by which amino acid catabolism is involved in microbial protein metabolites. In addition, results from several studies on the association of products from the intestinal metabolism of indigestible proteins and the state of health or disease of the host are revised.