Dietary Approaches for Japanese Patients with Diabetes: A Systematic Review

Determining Dietary Patterns to Recommend for Type 2 Diabetes: An Umbrella Review

Some specific dietary patterns improve glycaemic levels and cardiovascular risk factors better than others. We aimed to identify the most effective dietary patterns using a food-focused approach to improve blood glucose management (primary outcome) and cardiovascular risk factors (secondary outcome) in people with type 2 diabetes. An umbrella review was conducted comparing dietary patterns for the management of these outcomes. Studies published between 2012 and 2022 were identified using PubMed Central, ProQuest, Web of Science, and the Cochrane Database of Systematic Reviews. Thirty systematic reviews met the inclusion criteria. Twenty-two of thirty reviews quantitated (via meta-analyses of over 212 randomised control trials) the effect size of different dietary patterns. Twelve reviews found Low-carbohydrate (LC), Mediterranean (M), Plant-based (PB), and/or Low-glycaemic Index (LGI) diets reduced HbA1c moderately more than control diets (typically a high-carbohydrate, low-fat diet) (i.e., LC: -0.1 to -0.5%; M: -0.3 to -0.5%; PB: -0.2 to -0.4%; LGI -0.2 to -0.5%; all p-value < 0.01). We conclude that Low-carbohydrate, Mediterranean, Plant-based, and Low-glycaemic Index dietary patterns are all clinically effective for people with type 2 diabetes as alternatives to high-carbohydrate, low-fat diets typically used for managing glycaemic levels and CVD risk. However, quality evidence about the sustainability of effects and safety remains limited, warranting future research.

Fat, Sugar or Gut Microbiota in Reducing Cardiometabolic Risk: Does Diet Type Really Matter?

The incidence of cardiometabolic diseases, such as obesity, diabetes, and cardiovascular diseases, is constantly rising. Successful lifestyle changes may limit their incidence, which is why researchers focus on the role of nutrition in this context. The outcomes of studies carried out in past decades have influenced dietary guidelines, which primarily recommend reducing saturated fat as a therapeutic approach for cardiovascular disease prevention, while limiting the role of sugar due to its harmful effects. On the other hand, a low-carbohydrate diet (LCD) as a method of treatment remains controversial. A number of studies on the effect of LCDs on patients with type 2 diabetes mellitus proved that it is a safe and effective method of dietary management. As for the risk of cardiovascular diseases, the source of carbohydrates and fats corresponds with the mortality rate and protective effect of plant-derived components. Additionally, some recent studies have focused on the gut microbiota in relation to cardiometabolic diseases and diet as one of the leading factors affecting microbiota composition. Unfortunately, there is still no precise answer to the question of which a single nutrient plays the most important role in reducing cardiometabolic risk, and this review article presents the current state of the knowledge in this field.

Case Report: Metreleptin and SGLT2 Inhibitor Combination Therapy Is Effective for Acquired Incomplete Lipodystrophy

Childhood cancer survivors (CCSs) who have undergone bone marrow transplantation with systemic chemotherapy and whole-body irradiation often experience impaired glucose tolerance with marked insulin resistance. Incomplete acquired diabetic lipodystrophy should be considered as a late complication of bone marrow transplantation. A 24-year-old Japanese female patient with incomplete acquired lipodystrophy, a CCS of acute lymphocytic leukemia at the age of 3 years, was treated for diabetes mellitus and dyslipidemia at our hospital. Administration of multiple daily insulin injections (70 units/day), and oral administration of 500 mg/day metformin, 15 mg/day pioglitazone, and 200 mg/day bezafibrate had proven ineffective for her metabolic disorders. Subcutaneous administration of metreleptin improved her insulin resistance and hypertriglyceridemia within a month; however, it failed to maintain adequate plasma glucose levels in the long term. When oral administration of 10 mg/day empagliflozin was added to the metreleptin supplementation, her HbA1c value (National Glycohemoglobin Standardization Program) improved from 11% to 8%, which was maintained for an additional 18 months. This is the first case report of incomplete lipodystrophy that shows efficacy of a combination therapy with metreleptin and a sodium glucose cotransporter 2 (SGLT2) inhibitor for the treatment of diabetes and dyslipidemia. An SGLT2 inhibitor attenuates hyperglycemia through urinary glucose excretion and has been suggested to enhance lipid catabolism in the extra-adipose tissues, especially in the liver and skeletal muscles. Furthermore, metreleptin supplementation could enhance the action of the SGLT2 inhibitor by promoting satiety and lipolysis through the central nervous system. Combination therapy with metreleptin and an SGLT2 inhibitor was suggested to recover the volume of adipose tissue, possibly through improvement of insulin resistance in the adipose tissue. This report highlights the pathophysiological mechanism of an SGLT2 inhibitor in the improvement of glucose metabolism in non-healthy lean CCSs with insulin resistance. Administration of SGLT2 inhibitor, along with metreleptin supplementation, could be a good alternative therapy for diabetic lipodystrophy observed in CCSs.

Changes in Body Weight, Dysglycemia, and Dyslipidemia After Moderately Low-Carbohydrate Diet Education (LOCABO Challenge Program) Among Workers in Japan

PURPOSE

It is theorized that the prevalence of obesity has not decreased owing to poor adherence to implemented programs addressing metabolic syndrome, obesity, and diabetes in Japan. Therefore, we intended to evaluate the influence of a moderately low-carbohydrate diet on improving markers of metabolic syndrome among workers in Japan.

PATIENTS AND METHODS

Participants with metabolic syndrome or obesity were recruited based on the eligibility criteria for the Specific Health Guidance program and educated on a moderately low-carbohydrate diet between spring 2016 and fall 2018. The participants were then made to report their food intake and body weight once a week for the next 12 weeks and were counselled on maintaining a moderately low-carbohydrate diet. HbA1c levels, lipid profile, body weight, and sleep quality were evaluated. The normality of the data was evaluated using the Skewness/Kurtosis test. Each variable was compared before and after the intervention using the Wilcoxon signed-rank test. Further, a subgroup analysis of the data from the participants whose variables were abnormal at baseline was performed.

RESULTS

Among the 101 enrolled participants, a decrease in the median weight (from 82.5 to 79.7 kg, p<0.001, n=46), body mass index (from 27.3 to 26.9 kg/m², p<0.001, n=46), and apnea-hypopnea index (from 24.1 to 17.1, p<0.01, n=39) was observed. Subgroup analysis of participants with abnormal baseline values revealed changes in HbA1c (from 6.7% to 5.8%, p<0.001, n=34), total cholesterol (from 220 to 209 mg/dL, p<0.01, n=54), low-density lipoprotein cholesterol (from 133 to 120 mg/dL, p<0.001, n=31), high-density lipoprotein cholesterol (from 35 to 40 mg/dL, p<0.01, n=31), triglycerides (from 242 to 190 mg/dL, p<0.01, n=57), and deep sleep percentage (from 10.4% to 18.2%, p<0.05, n=7).

CONCLUSION

A moderately low-carbohydrate diet may be considered a potential intervention for improving the markers of metabolic syndrome, obesity, and diabetes.

Dietary Intake and Type 2 Diabetes

This editorial aims to examine the risk factors associated with type 2 diabetes and to discuss the evidence relating to dietary strategies for managing people with this condition. It is clear from the evidence presented that a range of dietary interventions can provide useful approaches for managing people with type 2 diabetes, including the regulation of blood glucose and lipid parameters, and for reducing the risks of acute and chronic diabetic complications.