Table 3 Overview of the studies in the complementary search for studies published between January 2015 and January 2019

Reaching Out and Preventing Increases in Diabetes (RAPID)

USA

Ackermann et al.,. 2014 [63]

Ackermann et al., 2015 [64]

Economically disadvantaged adults

≥18 years old, BMI ≥ 24 kg/m2, no prior T2D, HbA1c level 5.7–6.9% or FPG > 100–125 mg/dl

12,787 patients were identified from 9 primary care clinic database; 3064 identified as high risk by primary care glucose tests; 640 attended screening visit.

n = 509 (n = 252 for CG and n = 257 for IG)

sex: 29.3% men

age: 50.8 ± 12.2 y

Community-based randomized trial in economically disadvantaged adults. 2 groups: standard clinical advice plus a group-based adaption of the DPP offered by the YMCA, versus standard clinical advice alone.

Follow-up: 12 months.

Weight loss of 5–7%; moderate physical activity; lower dietary fat and total calorie consumption.

16 classroom-style behavioural counselling meetings, lasting 60 to 90 min and delivered over 16 to 20 weeks. Following monthly 60-min maintenance lessons until the end of the trial. YMCA offered limited guest-access and tools such as a step counter, measuring cups, fat and calorie tracking tools and recipe guides. Intervention was based on the DPP and included Goal-setting, self-monitoring and participant-centred problem solving.

Mean 12-month weight loss was 2.3 kg (95%CI: 1.1 to 3.4) more for the intervention arm than for standard care. Participants attending ≥9 lessons had a 5.3-kg (95% CI: 2.8 to 7.9) greater weight loss than did those with standard care alone. No significant differences in HbA1c, systolic blood pressure, HDL cholesterol or total cholesterol at 12 months.

(+)

Diabetes mellitus and abnormal glucose tolerance development after gestational diabetes

Spain

Pérez-Ferre et al., 2015 [65]

Women with prior gestational diabetes

Prior GDM, normal fasting glucose at 6–12 weeks postpartum

300 were invited

n = 260 were included (130 in IG and 130 in CG)

sex: 100% women

age: 35 y (range 31–38 y)

RCT in a hospital setting, Mediterranean lifestyle intervention vs. control.

Follow-up: 3 years (n = 237, 126 in IG and 111 in CG)

For both groups: Mediterranean diet, physical activity and smoking cessation. Goals for IG: ≥5 servings (svgs) fruits and vegetables /day, > 2 svgs legumes/week, > 3 svgs nuts / week, daily use of virgin olive oil, ≥3 svgs oily fish / week, < 2 svgs red and processed meat / week and < 2 svgs non-skimmed dairy products / week.

Intervention group: 2-h group session at the 1st visit + 5 individual reinforcement sessions (45-min) at the hospital + supervised exercise program: group and individual sessions (1-h, 4 days per week) for 10 weeks 3–6 months post-delivery and 3 reinforcement sessions. Exercise: intensive supervised program. Control group: 2-h group session at the 1st visit and 3 annual follow-up visits.

Less women in the IG (42.8%) developed glucose disorders compared with the CG (56.7%), p < 0.05.

Also significant reductions in BMI, waist circumference, insulin, HOMA-IR, LDL-cholesterol, triglycerides and Apo lipoprotein B in the IG compared with the CG.

++

Fit Body and Soul (FBAS) Study

USA

Dodani et al., 2009 [66]

Williams et al., 2013 [67]

Sattin et al., 2016 [68]

Rhodes et al., 2018 [69]

African-American in Georgia area

Age 20–64 years, self-described African American, BMI ≥25 kg/m², no plans for moving, non-diabetic

Study- trained church health advisors distributed flyers to church members and made scripted-podium announcements to promote the study.

710 subjects from 20 churches located in a Georgia metropolitan area consented.

n = 604 (n = 317 for IG and 287 for health education).

Single-blinded, cluster-randomized trial in African Americans. 2 groups: Fit Body and Soul intervention vs. health education (control).

Follow-up: 12 months.

Faith-based adaptation of the Group Lifestyle Balance program: weight reduction of ≥7% of initial weight and physical activity of ≥150 min per week of brisk walking.

Fit Body and Soul: The church health advisors held 12 weekly sessions comprised strategies to reduce calories and dietary fat, encourage physical activity, and behavioural modification such as stimulus control, goal setting, and problem solving followed by 6 monthly sessions. Health advisors phoned participants to review food and activity log and use scripted motivational interview messages to address participant barriers to lifestyle changes. Health education: 12 weekly sessions and then 6 monthly sessions, delivered by church health advisors including group discussion regarding health topics.

At 12 months, IG had a significant difference in adjusted weight loss compared with health education (2.39 kg vs. − 0.465 kg, p = 0.005) and were more likely to achieve a 7% weight loss (19% vs. 8%, p < 0.001). Fasting glucose did not differ between arms. In analyses with prediabetics only IG had a significant decline in fasting glucose compared to CG (− 12.38 mg/dl vs. +  4.44 mg/dl; p = 0.02).

Per-person intervention cost was $442.22 for IG vs. $391.83 for CG per-person.

+

Gestational Diabetes’ Effects on Moms (GEM) study

USA

Ferrara et al., 2014 [70]

Ferrara et al., 2016 [71]

Women with GDM history

Age ≥ 18 years, GDM diagnosis.

2480 identified;

n = 2.280 (1087 in lifestyle intervention and 1.193 in usual care).

sex: 100% women

Pragmatic cluster RCT of 2 groups in 44 medical facilities at Kaiser Permanente Northern California.

Follow-up: 12 months (n = 1420).

Reaching pregravid weight if pregravid BMI < 25 kg/m² or losing 5% of pregravid weight if their pregravid BMI ≥ 25 kg/m².

Intervention: 13 telephone sessions between 6 weeks and 6 months postpartum. Women were encouraged to set weekly goals for daily fat and caloric intake and to work up to 150 min of PA per week. Motivational interviewing and theoretical constructs from social cognitive theory and the transtheoretical model were used. 3 maintenance newsletters were mailed during 7–12 months post-partum.

Usual care: 2 pages of lifestyle recommendations sent via mail.

IG had a 28% higher odds (95%CI: 1.10–1.47) of meeting postpartum weight goals than CG. Women who completed all 13 sessions had double odds (OR: 2.16, 95%CI: 1.52, 3.07). Fewer women in the IG developed prediabetes or diabetes than in CG. However, HR for did not reach statistical significance.+

Fair Haven Community Health Center’s Diabetes Prevention Program

USA

Van Name et al., 2016 [72]

Low-income Hispanic women

Age 18–65 years, ≥ 1 risk factor for diabetes, OGTT.

1093 women identified as being at risk; 383 had prediabetes in OGTT.

n = 130

age: 43 y

sex: 100% women

RCT of 2 groups in low-income Hispanic women in Fair Haven community health centre

Follow-up: 12 months (n = 122)

Based on Diabetes Prevention Program: 7% weight loss (decreasing dietary fat and caloric intake) and ≥ 150 min per week of moderate-level physical activity.

IG: Family-centred 14-week group program with 1-h lifestyle class per week focusing on healthy food choices, behaviour change and weight loss led by a trained bilingual nurse. The curriculum was enhanced for a population with lower literacy with a hands-on learning approach including weekly cooking demonstrations, group learning sessions at the local grocery store, and encouragement to participate in the neighbourhood community farm. CG: 1 diabetes prevention counselling with nurse and dietitian.

The intensive intervention group lost 3.8 kg (4.4%), while the usual care group gained 1.4 kg (1.6%, p < 0.0001). 2-h glucose excursion decreased 15 mg/dL (0.85 mmol/L) in the intensive intervention group and 1 mg/dL (0.07 mmol/L) in the usual care group (p = 0.03). Significant decreases favoring intervention were also noted in BMI, percent body fat, waist circumference, and fasting insulin.

+

Community-based HEalthy Lifestyle intervention Program (Co-HELP)

Malaysia

Ibrahim et al.,2016 [73]

18–65 years old, able to read and understand Malay or English, fasting blood glucose 5.6–6.9 mmol/L, and/or 2-h glucose 7.8–11.0 mmol/L in 75 g OGTT, BMI 23–39 kg/m2

Recruiting from the general population through healthcare providers and presentations at community-halls, mosques, and media.

685 were screened

n = 268 (IG n = 122; CG n = 146)

sex: 35.8% men

age: 53 y

Quasi-experimental study with repeated measures, conducted in two sub-urban communities. 2 groups: intensive lifestyle intervention vs. standard care.

Follow-up: 12 months (n = 236)

Reduction of 5–10% of initial body weight for overweight and obese participants, reduction of calorie intake (20–25 kcal/kg body weight) and an increase from light to moderate physical activity (≥ 600 METs-minute/week).

IG received 12 90-min group sessions and ≥ 2 individual sessions with a dietitian and a researcher to reinforce behavioural change over 12 months. Sessions were first held more intensively (9 sessions /6 months) followed by 6 months maintenance phase with 3 monthly sessions (Sessions 10–12) and follow up through telephone calls or home visits for the last 3 months.

Other group got standard care in primary health care.

IG mean fasting glucose reduced by − 0.40 mmol/l (p < 0.001), 2-h post glucose by − 0.58 mmol/l (p < 0.001), HbA1C by − 0.24% (p < 0.001) and waist circumference by − 2.44 cm (p < 0.05). Greater proportion of IG met the weight loss target (24.6% vs. 3.4%, p < 0.001) and physical activity of > 600 METS/min/wk. (60.7% vs. 32.2%, p < 0.001) compared to the CG.

+

Lifestyle Modification in Information Technology (LIMIT)

India

Limaye et al., 2017 [74]

Employees in 2 IT industries

≥3 diabetes risk factors (family history of cardio-metabolic disease, overweight, high BP, IFG, high triglycerides, high LDL, low HDL).

437 employees in 2 multinational IT industries in Pune (India) were screened

n = 265 (132 in CG and 133 in IG);

age: 36.2 ± 9.3

RCT in 2 groups: Technology based lifestyle intervention

Follow-up: 1 year (n = 203)

5% weight loss for overweight/obese; 4 lifestyle modification goals: exercise ≥150 min/week, intake of giber-rich foods ≥8 servings/week, intake of calorie-dense foods ≤4 servings/week and smoking cessation.

Before randomization, all participants attended a 1-h group session on lifestyle modification.

Intervention group: information on lifestyle modification through 3 mobile phone messages and 2 e-mails per week for 1 year. Additional support was provided through a website and a Facebook page.

The prevalence of overweight/obesity reduced by 6.0% in the IG and increased by 6.8% in the CG (risk difference 11.2%; 95% CI: 1.2–21.1; P = 0.04). There were also significant improvements in lifestyle habits, waist circumference, and total and LDL cholesterol in the IG.

+

Promotora Effectiveness Versus Metformin Trial (PREVENT-DM)

USA

Perez et al., 2015 [75]

O’Brien et al., 2017 [76]

Socioeconomically disadvantaged Hispanic females in Philadelphia

Hispanic, female, age ≥ 20 y, Spanish-speaking, BMI ≥23 kg/m2, prediabetes*

573 women contacted in community health fairs and at community health centers; 441 were at high risk (ADA score ≥ 4); 197 were screened;

n = 92 (33 lifestyle, 29 metformin and 30 control);

sex: 100% women

age: 45.1 ± 12.5.

RCT in socioeconomically disadvantaged Hispanic women (Latinas). 3 groups: lifestyle intervention vs. metformin vs. control.

Follow-up: 12 months (n = 65, lifestyle 30, metformin 27 and CG 28)

Goals based on DPP: 5–7% weight loss by improving dietary patterns (decreasing fat and calorie consumption) and promoting moderate physical activity (≥150 min per week).

Group-based adaptation of the DPP intervention delivered by community health workers over 24 sessions (group size 5–9 participants, sessions lasting approx. 90 min). The first 14 sessions occurred weekly, and the final ten sessions took place biweekly and then monthly. Behavioural strategies such as goal setting, self-monitoring, stimulus control, and problem solving were used. Participants were provided with a digital scale, pedometer, measuring cups, and logs for tracking dietary intake and physical activity.

Post-hoc pairwise comparisons were significant for weight loss in lifestyle vs. standard care groups (−4.8 kg, p < 0.001) and lifestyle vs metformin (− 3.1 kg, p = 0.013), but not for metformin vs. standard care (− 1.7 kg, p = 0.3). Reduction in waist circumference was significantly greater in lifestyle than the standard care group (p = 0.001). Differences among groups in HbA1c did not reach statistical significance (p = 0.063).

+

Diabetes Prevention Program - Group Lifestyle Balance (DPP-GLB) in community centers

USA

Kramer et al., 2018 [77]

Age ≥ 18 y, BMI ≥24 kg/m2, presence of prediabetes*

and/or the metabolic syndrome

281 were screened

n = 134 were enrolled;

age: 62.5

Before-after study in 3 senior/community centers.

Follow-up: 12 months and to 18 months (n = 118 at 12 months; n = 107 at 18 months)

Goals Based on the DPP: 7% weight loss and increase physical activity to 150 min/week.

The Group Lifestyle Balance Program included 22 sessions delivered over a 1-year period (12 weekly sessions transitioning to monthly sessions) led by a lifestyle coach. Lifestyle coaches (2 registered dietitians and an exercise specialist) completed a standardized 2-day training workshop. A DVD of the initial 12 sessions, was developed to provide an additional option for program delivery.

At 12 months, a significant decrease in mean weight loss of, along with improvements in HbA1c, insulin, blood pressure and physical activity level. At 18 months significant improvements in mean weight waist circumference and physical activity.

+

Prevention of Diabetes in Euskadi (Pre-DE)

Spain

Sanchez et al., 2012 [78]

Sanchez et al., 2016 [79]

Sanchez et al., 2018 [80]

Age 40–75 years; FINDRISC ≥14; high risk according OGTT.

14 primary health centres selected; 66,293 individuals identified; 4170 screened; 2128 at risk for diabetes; 1314 had OGTT

n = 1088 enrolled (634 in CG, 454 in IG).

Cluster randomized clinical trial. Clusterded by primary health care centres to 2 groups.

Follow-up: 1 + 2 years (n = 872 in 12-month and 956 in 24-months).

Goals Based on the Diabetes in Europe-Prevention using Lifestyle, Physical Activity and Nutritional (DE-PLAN).

IG: Phase 1 consisted of intensive intervention through 4 1.5-h monthly educational sessions in small groups (10–15 patients) to encourage the adoption of healthy habits; Maintenance phase of regular contact with participants (at least once every 6 weeks) mainly via telephone calls from nurses. Control centers provided usual care.

Incidence of diabetes was 12.1% in the CG and 8.4% in IG, with an absolute difference of 3.8% (95% CI: 0.18 -7.4%, p = 0.045) and a relative risk reduction of 32% (0.68; 95% CI: 0.47–0.99, p = 0.048).

++

Kerala Diabetes Prevention Program (K-DPP)

India

Sathish et al., 2013 [81]

Mathews et al., 2018 [82]

Aziz et al., 2018 [83]

Thankappan et al., 2018 [84]

Age 30–60 years; Indian Diabetes Risk Score value of ≥60; absence of diabetes in OGTT.

3689 individuals were contacted through home visits; 1529 had Risk Score value of ≥60; 1209 attended community-based clinics;

n = 1007 were enrolled (500 in IG and 507 in CG).

age: 46 y

RCT in community settings in 2 groups.

Follow-up: 12 + 24 months (n = 964 at 24 months)

Goals: Increasing physical activity; promoting healthy eating habits; maintaining appropriate body weight by balancing calorie intake and physical activity; tobacco cessation; reducing alcohol consumption; ensuring adequate sleep.

Adapted from the Finnish Good Ageing in Lahti Region (GOAL) program and the Australian Greater Green Triangle (GGT) Diabetes Prevention Project. IG got 15 group sessions over 12 months (1 session delivered by the research team, 2 sessions by local experts and 12 sessions by trained lay peer leaders), a handbook of peer support and its role in lifestyle modification and a workbook to guide self-monitoring of lifestyle behaviours, goal setting and goal review. Both groups got health education booklet.

At 24 months, diabetes developed in 17.1% in CG and 14.9% in IG (RR: 0.88, 95% CI 0.66–1.16, p = 0.36). IG had significantly greater reduction in Indian Diabetes Risk Score and alcohol use and a greater increase in fruit and vegetable intake and physical functioning score of the HRQoL scale.

++

Jew and Bedouin women with recent GDM in the Negev area.

Israel

Zilberman-Kravits et al., 2018 [85]

Jewish and Bedouin women with prior GDM

prior GDM

307 women identified;

n = 180 (103 in IG, 77 in CG).

sex: 100% women

age: 35,6 y

n = 176 at 12-month follow-up; n = 104 at 24-month follow-up.

RCT in2 groups.

Follow-up: 1 and to 2 years after baseline (n = 176 at 12-months; n = 104 at 24-months)

Culturally adapted dietary and exercise recommendations for increase PA and decrease unhealthy foods.

The IG participated in healthy lifestyle sessions led by a dietician and a sports instructor for 24 months after delivery. Participants had 3 individual 45-min counselling sessions and 4 90-min group meetings (10 women each). Participants were given both verbal and written information, had the opportunity to practice physical activities during the meetings and received healthy meals that included low-fat products, such as yogurt, vegetables, fruits and whole-grains.

The intervention significantly reduced insulin, glucose and HOMA-IR levels compared with control (p < 0.001). Also significant differences in lipidemic profile, blood pressure and physical activity level between groups.

+