Long-Term Low-Carb Diets Effective for Dyslipidemia, Not Glycemic Control in Type 2 Diabetes: Study

The efficacy of long-term LCD in the management of type 2 diabetes is arguable. In spite of many trials in this respect, controversy still persists regarding the influence of such diets on glycemic control. Thus, the present meta-analysis sought to resolve this issue through data synthesis from multiple RCTs on long-term effects of LCD on glycemic control and other health outcomes.

A PubMed, Embase, and Cochrane Database search up to June 2023 for the identification of articles was undertaken. The inclusion criteria were RCTs of LCD interventions that had been conducted in people with T2D and having an intervention period of >12 months. Primary outcome: Change in HbA1c (long-term LCD vs control). Secondary outcomes were changes in SBP, DBP, LDL-C, HDL-C, TGs, and body weight.

Results

• Six studies met the inclusion criteria and were included in the analysis.

• The findings revealed no significant difference in changes in HbA1c levels between the long-term LCD and control diets (standardized mean difference [SMD] −0.11, 95% confidence interval [CI] −0.33 to 0.11, P = 0.32).

• No significant differences were observed in weight loss, blood pressure, and LDL-C between the two diet groups.

• Significant improvements were noted in lipid profiles for individuals on long-term LCD.

• These diets were associated with a greater increase in HDL-C (SMD 0.22, 95% CI 0.04–0.41, P = 0.02) and a greater reduction in triglycerides (SMD −0.19, 95% CI −0.37 to 0.02, P = 0.03) compared to control diets.

This meta-analysis indicates that, though there is no significant effect of long-term LCD on glycemic control in people with T2D, they do convey the most striking benefits toward the management of dyslipidemia. On the other hand, the increase in HDL-C and the decrease in triglycerides suggest that LCD might be an effective way to improve the lipid profiles important for cardiovascular health in patients with diabetes.

This systematic review updates the possible benefit of long-term low-carbohydrate diets in improving lipid parameters but not significantly enhancing glycemic control in people with T2D. Providers should consider these findings in counselling patients about dietary strategies for the management of diabetes and related metabolic diseases.

Reference:

Ichikawa, T., Okada, H., Hironaka, J., Nakajima, H., Okamura, T., Majima, S., Senmaru, T., Ushigome, E., Nakanishi, N., Hamaguchi, M., Joo, E., Shide, K., & Fukui, M. (2024). Efficacy of long‐term low carbohydrate diets for patients with type 2 diabetes: A systematic review and meta‐analysis. Journal of Diabetes Investigation. https://doi.org/10.1111/jdi.14271