Systematic review and meta-analysis of dietary carbohydrate restriction in patients with type 2 diabetes

OBJECTIVE: Nutrition therapy is an integral part of self-management education in patients with type 2 diabetes. Carbohydrates with a low glycemic index are recommended, but the ideal amount of carbohydrate in the diet is unclear. We performed a meta-analysis comparing diets containing low to moderate amounts of carbohydrate (LCD) (energy percentage below 45%) to diets containing high amounts of carbohydrate (HCD) in subjects with type 2 diabetes. RESEARCH DESIGN AND METHODS: We systematically reviewed Cochrane library databases, EMBASE, and MEDLINE in the period 2004–2014 for guidelines, meta-analyses, and randomized trials assessing the outcomes HbA1c, BMI, weight, LDL cholesterol, quality of life (QoL), and attrition. RESULTS: We identified 10 randomized trials comprising 1376 participants in total. In the first year of intervention, LCD was followed by a 0.34% lower HbA1c (3.7 mmol/mol) compared with HCD (95% CI 0.06 (0.7 mmol/mol), 0.63 (6.9 mmol/mol)). The greater the carbohydrate restriction, the greater the glucose-lowering effect (R=−0.85, p<0.01). At 1 year or later, however, HbA1c was similar in the 2 diet groups. The effect of the 2 types of diet on BMI/body weight, LDL cholesterol, QoL, and attrition rate was similar throughout interventions. LIMITATIONS: Glucose-lowering medication, the nutrition therapy, the amount of carbohydrate in the diet, glycemic index, fat and protein intake, baseline HbA1c, and adherence to the prescribed diets could all have affected the outcomes. CONCLUSIONS: Low to moderate carbohydrate diets have greater effect on glycemic control in type 2 diabetes compared with high-carbohydrate diets in the first year of intervention. The greater the carbohydrate restriction, the greater glucose lowering, a relationship that has not been demonstrated earlier. Apart from this lowering of HbA1c over the short term, there is no superiority of low-carbohydrate diets in terms of glycemic control, weight, or LDL cholesterol

Glucometabolic changes influence hospitalization and outcome in patients with COVID-19: An observational cohort study

AIMS: The aim was to report the prevalence of diabetes status in patients hospitalized with COVID-19 and assess the association between the glucometabolic status at admission and 90-day mortality. METHODS: Consecutive patients hospitalized with COVID-19 were included in the study. All participants included had an HbA(1c) measurement 60 days prior to or within 7 days after admission. We studied the association between diabetes status, the glycemic gap (difference between admission and habitual status), admission plasma-glucose, and mortality using Cox proportional hazards regression. RESULTS: Of 674 patients included, 114 (17%) had normal glucose level, 287 (43%) had pre-diabetes, 74 (11%) had new-onset, and 199 (30%) had diagnosed diabetes. No association between diabetes status, plasma-glucose at admission, and mortality was found. Compared to the 2nd quartile (reference) of glycemic-gap, those with the highest glycemic gap had increased mortality (3rd (HR 2.38 [1.29–4.38], p = 0.005) and 4th quartile (HR 2.48 [1.37–4.52], p = 0.002). CONCLUSION: Abnormal glucose metabolism was highly prevalent among patients hospitalized with COVID-19. Diabetes status per se or admission plasma-glucose was not associated with a poorer outcome. However, a high glycemic gap was associated with increased risk of mortality, suggesting that, irrespective of diabetes status, glycemic stress serves as an important prognostic marker for mortality