Yamada 2014.
| Study characteristics | ||
| Methods |
Review comparison(s) addressed by this study: 3 Study design: RCT, parallel, single‐centre (1) Trial registry number: NR Total number of trial arms: 2 Year trial started: 2011 Sample size calculation: Yes Outcome(s) used for sample size calculation: Change in HbA1c Duration of run‐in period (weeks): NA What was the duration of the weight loss phase: 6 months What was the duration of the weight maintenance phase: NA Other notes about methods: NA |
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| Participants |
Country and setting: Japan, outpatient clinic at hospital diabetes centre in Tokyo Eligibility criteria: Participants with type 2 diabetes who had received guidance on caloric restriction at least once with an HbA1c level between 6.9 and 8.4%. Participants were excluded if they had specified ranges of proteinuria, serum creatinine, aspartate aminotransferase or alanine aminotransferase; had history of myocardial infarction or stroke in the past six months; experienced an absolute change in HbA1c of > 1.0% in the past six months or had ketosis (to avoid ketoacidosis as a complication). Type 2 diabetes at baseline: Yes Impaired glucose tolerance at baseline: No Cardiovascular conditions/risk factors/events at baseline: Unclear Gender: Mixed Total number randomised: 24 Total attrition in trial: 0 Treatment diet Participants randomised: 12 Participants withdrawn (voluntary): 0 Total attrition: 0 Control diet: Participants randomised: 12 Participants withdrawn (voluntary): 0 Total attrition: 0 Baseline data treatment diet: Randomised participants not included: None Age (years): mean (SD) 63.3 (13.5) Gender distribution (as reported): female 5/12, male 7/12 Weight (kg): mean (SD) 67.0 (15.9) BMI (kg/m2): mean (SD) 24.5 (4.3) DBP (mmHg): mean (SD) 72.6 (6.2) SBP (mmHg): mean (SD) 124.4 (10.8) HbA1c (%): mean (SD) 7.6 (0.4) LDL (mmol/L): mean (SD) 2.58 (0.73) HDL (mmol/L): mean (SD) 1.63 (0.44) Non‐HDL (mmol/L): NR TC (mmol/L): NR TG (mmol/L): mean (SD) 1.60 (0.86) Baseline data control diet: Randomised participants not included: None Age (years): mean (SD) 63.2 (10.2) Gender distribution (as reported): female 7/12, male 5/12 Weight (kg): mean (SD) 68.1 (7.7) BMI (kg/m2): mean (SD) 27.0 (3.0) DBP (mmHg): mean (SD) 74.8 (10.6) SBP (mmHg): mean (SD) 124.9 (10.7) HbA1c (%): mean (SD) 7.7 (0.6) LDL (mmol/L): mean (SD) 2.91 (0.53) HDL (mmol/L): mean (SD) 1.55 (0.49) Non‐HDL (mmol/L): NR TC (mmol/L): NR TG (mmol/L): mean (SD) 1.75 (0.98) Group differences at baseline: No Characteristic(s) with significant group difference and relevant statistic: NA Other notes about participants: Patients are Japanese, BMI cutoff is different for overweight and obesity. |
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| Interventions |
Energy (E) comparison of treatment vs control diets: Different ‐ ad libitum in treatment diet and restricted in control diet Treatment diet: Name (as reported) and brief description: Low‐carbohydrate diet consumed ad libitum, total carbohydrate intake set at < 130 g/day but with a lower limit of 70 g/day to prevent ketosis. The intake was distributed across meals with 20 to 40 g/meal and 5 g of carbohydrates from sweets twice daily. Treatment diet type (carbohydrate‐fat‐protein): Low‐unclear‐unclear Exercise component? No Recipients: Participants were type 2 diabetics, 41.7% female and aged 63.3 (13.5) years, with BMI 24.5 (4.3) and weight 67.0 (15.9) kg, mean HbA1c of 7.6%. Why? The American Diabetes Association has recommended that controlling carbohydrate intake should form part of treating diabetes. The ADA has also recognised low‐carbohydrate diets as an intervention which is effective for weight reduction. Dietary adherence to calorie‐restricted diets may be difficult to sustain over the long term. Low carbohydrate diets may be used as a treatment option in diabetics as well as assist with weight loss, blood glucose and lipid management. What (materials)? Recommendation as per Accurso et al (2008). Citation: Accurso A, Bernstein RK, Dahlgvist A, et al. Dietary carbohydrate restriction in type 2 diabetes mellitus and metabolic syndrome: time for a critical appraisal. Nutr Metab (Lond) 5: 9, 2008. What (procedures)? Participants were assigned to the low‐carbohydrate diet (> 70 g/day and < 130 g/day), with target carbohydrate contents per meal prescribed. Consultations with diet instructions and assessments every 2 months were conducted. Who provided? Four registered dietitians instructed participants. How and where? Face‐to‐face, location at outpatient clinics When and how much? Intervention duration was six months with 2‐monthly follow‐up visits. Duration and frequency of instruction NR Strategies to improve or maintain fidelity; tailoring and modification: NR Extent of intervention fidelity: "The mean carbohydrate intake in the low carbohydrate group was < 130 g/day, suggesting that most patients were able to adhere to the meal instructions." Macronutrient intakes for carbohydrates, protein and fat were 29.8 (12.5)%, 25.3 (7.3)% and 45.4 (8.9)%. Concomitant interventions: Participants were on insulin (25.0%), metformin (41.7%), sulfonylurea (41.7%), glinide (8.3%), thiazolidinedione (33.3%), alpha‐glucosidase inhibitor (16.7%), DPP‐4 inhibitor (16.7%). All participants were on some form of glucose‐lowering drug; none were taking GLP‐1. Control diet: Name (as reported) and brief description: Calorie‐restricted diet as defined by the Japan Diabetes Society, with target macronutrient intakes of 50 to 60% carbohydrates, < 20% protein and < 25% fat. Target calorie intake was defined as total calorie intake (kcal) = ideal body weight × 25. Control diet type (carbohydrate‐fat‐protein): Balanced‐balanced‐balanced Exercise component? No Recipients: Participants were type 2 diabetics, 58.3% female and aged 63.2 (10.2) years, with BMI 27.0 (3.0) and weight 68.1 (7.7) kg, mean HbA1c of 7.7%. Why? The American Diabetes Association recognises caloric restriction as an effective strategy to reducing body weight. The Japan Diabetes Society also currently recommends caloric restriction for the management of blood glucose. What (materials)? Recommendations of the Japan Diabetes Society. Citation: The Japan Diabetes Society. Diet therapy. In Practice Guideline for the Treatment for Diabetes in Japan; Nankodo: Tokyo, Japan, 2016; pp. 37–66. (In Japanese). What (procedures)? Participants were assigned to caloric restriction and the calculation of calorie intake through the classification of macronutrients. Who provided? Four registered dietitians instructed participants. How and where? Face‐to‐face, location at outpatient clinics When and how much? Intervention duration was six months with 2‐monthly follow‐up visits. Duration and frequency of instruction NR Strategies to improve or maintain fidelity; tailoring and modification: NR Extent of intervention fidelity: Macronutrient intakes for carbohydrates, protein and fat were 51.0 (4.6)%, 16.6 (2.8)% and 32.3 (5.2)%. Concomitant interventions: Participants were on insulin (33.3%), metformin (8.3%), sulfonylurea (66.7%), thiazolidinedione (50.0%), DPP‐4 inhibitor (25.0%). All participants were on some form of glucose‐lowering drug; none were taking GLP‐1, glinide or alpha‐glucosidase inhibitor. |
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| Outcomes |
Change in body weight (kg) at 3 to < 12 months: Yes Change in body weight (kg) at ≥ 12 months: No Number of participants with 5% weight loss from baseline at 3 to < 12 months: No Number of participants with 5% weight loss from baseline at ≥ 12 months: No Change in BMI (kg/m2) at 3 to 12 months: Yes Change in BMI (kg/m2) at ≥ 12 months: No Number of participants with 5% BMI reduction from baseline at 3 to 12 months: No Number of participants with 5% BMI reduction from baseline at ≥ 12 months: No Change in DBP (mmHg) at ≥ 12 months: No Change in SBP (mmHg) at ≥ 12 months: No All‐cause mortality at ≥ 12 months: No Cardiovascular mortality at ≥ 12 months: No Non‐fatal myocardial infarction at ≥ 12 months: No Non‐fatal stroke at ≥ 12 months: No Diagnosis of type 2 diabetes mellitus at ≥ 12 months: No Change in HbA1c (%) at ≥ 12 months: No Change in LDL (mmol/L) at ≥ 12 months: No Change in HDL (mmol/L) at ≥ 12 months: No Change in non‐HDL (mmom/L) at ≥ 12 months: No Change in total cholesterol (TC) (mmol/L) at ≥ 12 months: No Change in triglycerides (or triacylglycerides) (TG) (mmol/L) at ≥ 12 months: No Participant‐reported adverse effects: No |
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| Notes |
Number and type of records(s): journal article Trial acronym/name: None Trial funded by: NR Declaration of interest: "The authors state that they have no Conflict of Interest (COI)." |
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ACE: angiotensin‐converting enzyme ADA: American Dietetic Association ALT: alanine aminotransferase AMDR: Acceptable Macronutrient Distribution Range APMD: adequate protein medium dairy ASA24: Automated Self‐Administered 24‐h Dietary Recall AST: aspartate aminotransferase AUD: Australian dollar BCCA: branched‐chain amino acids BMD: bone mineral density BMI: body mass index BP: blood pressure Ca2+: calcium CARB: carbohydrate CD: compact disc CGMS: Continuous Glucose Measuring System CHO: carbohydrate CI: confidence interval CON: control CRC: Clinic Research Centre CRD: calorie‐restricted diet CSIRO: Commonwealth Scientific and Industrial Research Organisation CVD: cardiovascular disease C‐WL: control weight loss DBP: diastolic blood pressure DEXA: dual‐energy X‐ray absorptiometry DGE: Deutsche Gesellschaft für Ernährung (German Nutrition Society) DM: diabetes mellitus DRI: Dietary Reference Intake E: energy ER: energy restriction ESHA: Elizabeth Stewart Hands and Associates FFQ: food frequency questionnaire FM: fat mass FMD: flow‐mediated dilatation GCRC: General Clinical Research Centre GI: glycaemic index GL: glycaemic load GLP‐1: glucagon‐like peptide‐1 HbA1c: haemoglobin A1c/glycated haemoglobin HBV: high biological value HC: high‐carbohydrate HCD: high‐carbohydrate diet HDL(‐C): high‐density lipoprotein(‐cholesterol) HCLF: high‐carbohydrate low‐fat HDPMC: high‐dairy protein, moderate‐carbohydrate HF: high‐fat HFLC: high‐fat low‐carbohydrate HNP: high‐normal‐protein HOMA‐BCF: homeostatic model assessment of β‐cell function HOMA‐IR: homeostatic model assessment for insulin resistance HP: high‐protein HPHD: high‐protein high‐dairy HP‐WL: high‐protein weight‐loss HRT: hormone replacement therapy HUF: high‐unsaturated fat IFG: impaired fasting glucose iGFR: isotope glomerular filtration rate INS: insulin sensitivity IQR: interquartile range IR: insulin resistant/resistance IS: insulin sensitive/sensitivity ITT: intent(ion)‐to‐treat kcal: kilocalorie kg: kilogram LC: low‐carbohydrate LCD: low‐carbohydrate diet LCHP: low‐carbohydrate high‐protein LCK: low‐carbohydrate ketogenic LCKD: low‐carbohydrate ketogenic diet LCM: low‐carbohydrate Mediterranean LDL(‐C): low‐density lipoprotein(‐cholesterol) LF: low‐fat LFD: low‐fat diet LFHC: low‐fat high‐carbohydrate LGI: low‐glycaemic index LGID: low‐glycaemic index diet LGL: low‐glycaemic load LOGI: energy‐restricted low‐carbohydrate MCCR: moderate‐carbohydrate calorie‐restricted MLC: modified low‐carbohydrate MES: medication effect score MF: modified‐fat high‐carbohydrate MI: initial weight maintenance period MII: final weight maintenance period MN: micronucleus MUFA: monounsaturated fatty acid NA: not applicable NAFLD: non‐alcoholic fatty liver disease NCEP: (United States) National Cholesterol Education Program NIH: National Insitutes of Health NNR: Nordic Nutrition Recommendations NR: not reported NSAID: non‐steroidal anti‐inflammatory drug NU: nitrogen excretion in urine OGTT: oral glucose tolerance test PA: physical activity PABA: para‐aminobenzoic acid PD: Paleolithic diet PBL: peripheral blood lymphocytes PRO: protein PUFA: polyunsaturated fatty acid
1RM: one‐repetition maximum RCT: randomised controlled trial RD: registered dietitian RDA: Recommended Dietary Allowance REE: resting energy expenditure REX: resistance exercise RMR: resting metabolic rate SBP: systolic blood pressure SD: standard deviation SE: standard error SEM: standard error of the mean SFA: saturated fatty acid T2DM: type 2 diabetes mellitus TAG: triacylglyceride TC: total cholesterol TE: total energy TG: triglyceride TM: traditional Mediterranean UCR: urea/creatinine ratio VHFLC: very high‐fat low‐carbohydrate VLC: very low‐carbohydrate VLCHF: very low‐carbohydrate high‐fat WHO: World Health Organization