Table 2 Overview of the studies targeting participants age 18–45 years and with minimum follow-up time 6 months

Daqing Diabetes Prevention Study

China

Pan et al., 1997 [5]

Li et al., 2008 [15]

People living in Daqing area, > 18 y old

IGT

110,660 people screened with OGTT

577 randomized

sex: 54% men

age: 45 ± 9 y

Cluster randomized controlled study in four groups: control, diet only, physical activity (PA) only, or diet + PA

FU 6 years (n = 533) + 20 years.

Goals: Diet (increase vegetables, decrease alcohol and sugar, caloric and weight reduction if overweight), PA (1–2 units/day; e.g. 30 min of slow walking etc.)

Individual counselling + compliance evaluation by physician/nurse every 3 months + small groups weekly for 1 month, monthly for 3 months and every 3 months thereafter. Intervention duration was 6 years.

HRs (adjusted for baseline BMI and f-Glu): HR = 0.69 for diet vs CG, p < 0.03; HR = 0.54 for diet + PA, p < 0.0005; 0.58 (diet+PA), p < 0.005; HR = 0.41 for PA vs CG p < 0.0005. The average number of PA units per day was higher after 6 years.

++

Hoorn Prevention Study

The Netherlands

Lakerveld et al., 2012 [26]

Lakerveld et al., 2013 [27]

Age 30–50

At least 10% risk for T2D and/or CVD estimated according formula of ARIC and SCORE projects.

A screening invitation to GP customers (n = 8193). 2401 respond, 921 eligible based on waist circumference. 772 were screened.

n = 622

sex: 42% men

age: 43.5 years

RCT in general practice.

FU 12 months (n = 502).

Goals were at least one fruit, at least 200 g vegetables and at least 30 min PA per day.

Participants were offered 6 face-to-face sessions (30 min) and 3 monthly telephone sessions with trained nurses. Methods were based on motivational interviewing, problem solving treatment, theory of planned behaviour and theory of self-regulation. CG got brochures of health guidelines.

No significant results in weight or fasting glucose or glucose tolerance. Increase in fruit intake between baseline and 6 months (1.1 - > 1.3 pieces per day) but not after 12 months. Median participation in sessions was 2.

(−)

Zhiiwapenewin Akino’maagewin: Teaching to Prevent Diabetes, ZATPD

Canada

Ho et al., 2008 [57]

Native North Americans

Native North Americans (=high T2D risk), non-pregnant, living in the community at least 30 days.

Screening from the community, IG n = 57, CG n = 38.

n = 133

sex: 22% men

age: 42 y

Non-random assignment of communities into intervention/ comparison

FU 12 months (n = 95).

Improve dietary choices (reduce fat and sugared drinks) and physical activity by increasing knowledge, self-efficacy, and attitudes.

Intervention was based on social cognitive theory of behaviour change and implemented in three components. School component with 16 + 17 sessions lead by teacher; children as “change agents”. Store component to support more appropriate foods. Community component, media involvement, cooking demos, community events, family fun nights in collaboration with existing health and social services.

Higher healthy food acquisition scores after intervention; no change in healthiness of food preparation scores. No change in BMI, decrease in PA in both groups

(+)

Making the Connection Healthy Living Program, MTC HLP

USA

Ruggiero et al., 2011 [36]

underserved latino population; age 18–65 years;

BMI > 24.9, normal glucose or prediabetes; Latin background

Community-based health screening events (schools, family centers, hospital etc). 1162 screened, 367 tested for eligibility, 244 eligible.

n = 69,

sex: 7% men

age: 38 y

Single-group, non-randomized follow-up, community-based translation of DPP.

FU 12 months (n = 57).

DPP goals: Weight reduction 7%; Diet: fat 25 E%

Physical activity (e.g. brisk walking) 150 min/week

Culturally specific intervention was developed and conducted in collaboration with the community to minimize barriers to participation education, literacy, language, income, transportation, lack of medical coverage. 22 group sessions during 1 year, delivered by trained community health workers. Cook books, pedometer, scales provided. Group walks arranged. Participants attended 57% of group sessions.

At 6 m, 20% achieved 7% weight reduction, and at 12 m 16% achieved. Moderate improvements in body weight (− 4.8 kg at 6 m, − 2.8 at 12 m), waist, fruit and vegetables, fat intake, PA were observed at 6 m but attenuated at 12 m. Forward movement in “stages of change” scale was observed.

+

Families United

USA

Perez Siwik et al., 2012 [58]

Kutob et al., 2014 [59]

Families with risk for T2D

Diabetes risk factor (BMI > 25, inactivity, family history, etc.), no T2D, not pregnant, able to participate in group sessions

Community and clinic-based recruitment, 164 were interested, 108 screened

n = 29 (+ 29 support people)

sex: 26% men

age: 45

Pretest-posttest study. Family-based intervention based on DPP. A household member/friend accompanied in the sessions.

FU 12 months (n = 18)

DPP goals (7% weight reduction, 150 min of PA/week); reduction in portion sizes and carbohydrates, especially sugared beverage, fat and fast food.

Patient-centered, multiculturally tailored intervention to elicit participants’ explanatory models regarding their diabetes risk. Physician+dietician delivered 12 group visits every 2 weeks over 6 months + 2 booster sessions. Cognitive behavioural approach aimed at increasing resilience (flexible thinking) skills. 15 min PA during each session. Attendance rate was 72% for the finishers.

Outcome measures were reduction in the total number of predefined diabetes risk factors (BMI, WC, BP, HbA1c, Insulin, GI, PA). Number of predefined risk factors reduced from 4.8 to 4.1 at 6 months and to 3.4 at 12 months, primarily due to reduction in GI and fasting insulin.

+

“Diabetes prevention program in public housing communities”

USA

Whittemore et al., 2013 [60]

Whittemore et al., 2014 [61]

People living in low-income public housing communities

age > 21 y, 2 or more T2D risk factors (overweight, age, family history)

Convenience sample in 4 rural public housing communities.

n = 67,

sex: 79% female

age: 40 y

Cluster-randomized implementation of DPP in low-income public housing communities. Enhanced standard care vs. mDPP, n = 67, diverse ethnicity (aim n = 100).

FU 6 months (n = 48)

DPP goals: Healthy eating plan, reduced calories, weight reduction 5–10%, physical activity 150 min/week

DPP program modified after focus groups. Two homecare nurses (8 h training) implemented the program and local community health workers (4 h training) assisted. IG got 7 interactive education classes during 6 months based on behavioural support on goal-setting, self-monitoring; problem-solving + gift-card raffles. CG got written information + two interactive education classes

No changes in body weight or other clinical risk factors, or behavioural or psychological outcomes.

(−)

DH!AAN

The Netherlands

Admiraal et al., 2013 [48]

Vlaar et al., 2012 [49]

South Asian migrants

Age 18–60 y; IFG, IGT, HbA1c > 6,0% or HOMA-IR > 2.39

2307 screened via general practices (invitation letter with reply card), followed by reminder and telephone call).

n = 536

age: 44.9 y

sex: 49.4% men

RCT in general practice among South Asian migrants in Netherlands getting a culturally targeted intervention or generic lifestyle advice (control).

FU 2 years (n = 335).

Goals according to SLIM study; based on current guidelines on diet and physical activity.

6–8 individual sessions in general practice during 6 months, 2 sessions during the next 6 months + 1 family session + two cooking classes. 20-week supervised exercise program was offered. Trained dieticians gave dietary counselling using motivational interviewing. Participants got a gift coupon for participating in baseline measurements. Control arm got 2 group sessions + 2 flyers.

No significant results. Median participation in 5 individual sessions. High drop-out and low participation 26% participated in family session, 26% in cooking sessions and 22% in PA sessions.

(−)

“Lifestyle modifications in Chinese women who had gestational diabetes mellitus”

China

Shek et al., 2014 [54]

Age > 18 years; GDM history; IGT 6–8 weeks after delivery; excluded if insulin for GDM

Patients from hospitals were invited if criteria were fulfilled

n = 450;

sex: 100% women

age: 39 y

RCT conducted in hospital in Hong Kong. Intensive lifestyle intervention vs. no intervention (control).

FU 36 months (n = 423).

Optimal caloric intake (based on Harris-Benedict) for ideal body weight

7 individual sessions in 3 years (3 m, 6 m 12 m, 18 m, 24 m, 30 m, 36 m). Dietician and study nurse gave individual dietary and exercise advice based on food and exercise records (n = 7).

In women > 40 years the difference in cumulative incidence of diabetes between groups was significant. Significant differences at 1 y measurements in BMI and waist-hip ratios, but not significant at 3 y in the end of the study.

(+)

Dulce Mothers

USA

Philis-Tsimikas et al., 2014 [62]

Low-SES Latinas

Latina, 18-45y, GDM during past 3 years

263 contacted by information from medical records, 193 met criteria, 102 consented and came to lab

n = 84

sex: 100% women

age: 31.9 y

Single-group, pretest-posttest

6 m follow-up (n = 70)

DPP goals: Weight reduction 7%, diet: fat 25 E%, physical activity (e.g. brisk walking) 150 min/week (700 kcal/week)

Condensed DPP based on social cognitive theory; trained peer educator lead educational group sessions, 8 sessions/8 weeks (core intervention) + additional monthly maintenance sessions e.g. weekly healthy lifestyle goals that involve the family members + discussions about culturally driven fatalistic health beliefs, mean attendance in 6 out of 8 sessions

No significant weight loss; however correlation between attendance and weight reduction.

HbA1c increased slightly (5.73- > 5.82). Moderate improvement in cholesterol, LDL, triglyserides and diastolic BP.

(+)