Table 17 The relationship between physical activity and the development of type 2 diabetes.

Haapanen et al 1997 [77]

To examine the association of PA and the risk of CHD, hypertension and T2D.

• n = 1,340 men, 1,500 women

10 yr follow-up

Number of cases: 118

LTPA has a preventive effect on T2D.

• Age: 35-63 yr

PA assessment: Self-reported

Age-adjusted RR (95% CI), men

Finland

LTPA (kcal/wk), divided into groups

• G1 = 1.54 (0.83-2.84)

• G2 = 1.21 (0.63-2.31)

Prospective cohort

• G3 = 1.00 (referent)

p = 0.374

Men

D & B score = 14

G1 = 0-1100

Age-adjusted RR (95% CI), women

G2 = 1101-1900

• G1 = 2.64 (1.28-5.44)

G3 = >1900

• G2 = 1.17 (0.50-2.70)

• G3 = 1.00 (referent)

Women (kcal/wk)

p < 0.006

G1 = 0-900

G2 = 901-1500

G3 = >1500

Cox proportional HR

Hu et al 2003 [111]

To examine the relationship between sedentary behaviours (particularly prolonged television watching) and risk of obesity and T2D in women.

• n = 68,497 (diabetes specific analyses)

6 yr follow-up

Number of cases: 1515

Sedentary behaviours (especially television watching) are associated with an increased risk for obesity and T2D.

USA

• n = 50,277 (obesity specific analyses)

PA assessment: Self-reported PA and sedentary behaviour

Each 2-h/d increment in TV watching was associated with a 23% (95% CI, 17%-30%) increase in obesity and a 14% (95% CI, 5%- 23%) increase in risk of T2D

Prospective cohort

• Age: 30-55 yr

Outcome measure: onset of obesity and T2D

Each 2-h/d increment in sitting at work was associated with a 5% (95% CI, 0%-10%) increase in obesity and a 7% (95% CI, 0%- 16%) increase in T2D

Light to moderate PA was associated with a significantly lower risk for obesity and T2D.

D & B score = 13

• Sex: Women

Multivariate analyses adjusting for age, smoking, dietary factors, and other covariates

Standing or walking around at home (2 h/d) was associated with a 9% (95% CI, 6%-12%) reduction in obesity and a 12% (95% CI, 7%- 16%) reduction in T2D

• Characteristics:

Each 1 hour per day of brisk walking was associated with a 24% (95% CI, 19%-29%) reduction in obesity and a 34% (95% CI, 27%- 41%) reduction in T2D

Free of T2D, CVD, or cancer at baseline

• Nurses' Health Study

Manson et al 1992 [112]

To examine the association between regular exercise and the subsequent development of T2D.

• n = 21,271

5 yr follow-up

Number of cases: 285

Exercise appears to reduce the development of T2D even after adjusting for BMI.

• Sex: Men

PA assessment: Questionnaire Fpr VPA (enough to develop sweat)

• Age: 40-84 yr

The age-adjusted incidence of T2D:

USA

• Characteristics:

• 369 cases per 100,000 person- years in men who engaged in VPA less than once weekly

• 214 cases per 100,000 person- years in those exercising at least five times per week (p trend < 0.001)

Free of diagnosed diabetes, CVD and cancer at baseline

Prospective cohort

D & B score = 14

Exercise frequency (times/wk)

G1 = < Weekly

G2 = At least weekly

Age-adjusted RR (95% CI) by exercise frequency

Times per week

G1 = 0

• G1 = 1.00 (referent)

G2 = 1

• G2 = 0.64 (0.51- 0.82)

G3 = 2-4

G4 = >5

Age-adjusted RR (95% CI) by exercise frequency

• G1 = 1.00 (referent)

Outcome measure: Incidence T2D

• G2 = 0.77 (0.55-1.07)

• G3 = 0.62 (0.46-0.82)

• G4 = 0.58 (0.40-0.84)

Age- and BMI-adjusted RR (95%

CI) by exercise frequency

• G1 = 1.00 (referent)

• G2 = 0.71 (0.56- 0.91)

Age- and BMI-adjusted RR (95% CI) by exercise frequency

• G1 = 1.00 (referent)

• G2 = 0.78 (0.56-1.09)

• G3 = 0.68 (0.51-0.90)

• G4 = 0.71 (0.49-1.03)

Hu et al. 2001[114]

To examine the relationship between dietary and lifestyle factors in relation to the risk for T2D.

• n = 84,941

16 yr follow-up

Number of cases: 3300

The majority of T2D could be prevented through healthy living.

• Sex: Women

• Age: 40-75 yr

PA assessment: Questionnaire For PA (h/wk), divided into groups

Multivariate-adjusted RR (95%)

USA

• Characteristics: participants had no history of diabetes, CVD, or cancer.

• Q1 = 1.00 (referent)

• Q2 = 0.89 (0.77-1.02)

Retrospective cohort

• Q3 = 0.87 (0.75-1.00)

Q1 = <0.5

• Q4 = 0.83 (0.71-0.96)

Q2 = 0.5--1.9

• Q5 = 0.71 (0.56--0.90)

D & B score = 13

Nurses' Health Study

Q3 = 2.0--3.9

Q4 = 4.0--6.9

Q5 = ≥7.0

Outcome measure: Incidence of T2D

Cox regression

Sato et al 2007 [116]

To examine the relationship between walking to work and the development of T2D.

• n = 8,576

4 yr follow-up

Number of cases: 878

The duration of a walk to work is an independent predictor of the risk for T2D.

• Sex: Men

• Age: 40--55 yr

PA assessment: For time spent walking to work, divided into tertiles

OR (95% CI)

Japan

• Kansai Healthcare Study

• T1 = 1.00 (referent)

• T2 = 0.86 (0.70-1.06)

Prospective cohort

T1 = 0-10 min

• T3 = 0.73 (0.58-0.92)

T2 = 11-20 min

Significant difference was seen between ≤ 10 min and ≤ 20 min only (p = 0.007)

T3 = ≥20 min

D & B score = 14

Outcome measure: Incidence of T2D

Hu G et al 2003 [117]

To examine the relationship of OPA, commuting and LTPA with the incidence of T2D.

• n = 14,290

PA assessment: Questionnaire For OPA, LTPA and commuting PA

Multivariate adjusted HR (95% Cl) for OPA, men

Moderate and high OPA, commuting PA or LTPA significantly reduces risk of T2D in middle aged adults.

• Sex: Men and women

• G1 = 1.00 (referent)

Finland

• Age: 35-64 yr

• G2 = 0.67 (0.44-1.01)

• Characteristic:

OPA

• G3 = 0.73 (0.52-1.02)

Prospective cohort

Asymptomatic for stroke, CHD, or diabetes at baseline.

G1 = Light (sitting)

G2 = Moderate (standing, walking)

Multivariate adjusted HR (95% Cl) for OPA, women

D & B score = 12

G3 = Active (walking, lifting)

• G1 = 1.00 (referent)

• G2 = 0.72 (0.46-1.12)

• G3 = 0.78 (0.52-1.18)

Commuting PA (min/d)

G1 = None

Multivariate adjusted HR (95% Cl) for OPA, men and women

G2 = 1-29

G3 = ≥ 30

G1 = 1.00 (referent)

G2 = 0.70 (0.52-0.96)

LTPA

G3 = 0.74 (0.57-0.95)

• G1 = Low (inactive)

• G2 = Moderate (walking, cycling >4 hr/wk)

Multivariate adjusted HR (95% Cl) for commuting PA, men

• G3 = High (running, jogging >3 hr/wk)

• G1 = 1.00 (referent)

• G2 = 1.00 (0.71-1.42)

Outcome measure: incidence of T2D

• G3 = 0.75 (0.46-1.23)

Multivariate adjusted HR (95% Cl) for commuting PA, women

Cox proportional HR

• G1 = 1.00 (referent)

• G2 = 0.94 (0.63-1.42)

• G3 = 0.57 (0.34-0.96)

Multivariate adjusted HR (95% Cl) for commuting PA, men and women

• G1 = 1.00 (referent)

• G2 = 0.96 (0.74-1.25)

• G3 = 0.64 (0.45-0.92)

Multivariate adjusted HR (95% Cl) for LTPA, men

• G1 = 1.00 (referent)

• G2 = 0.78 (0.57-1.06)

• G3 = 0.84 (0.52-1.37)

Multivariate adjusted HR (95% Cl) for LTPA, women

• G1 = 1.00 (referent)

• G2 = 0.81 (0.58-1.15)

• G3 = 0.85 (0.43 -1.66)

Multivariate adjusted HR (95% Cl) for LTPA, men and women

• G1 = 1.00 (referent)

• G2 = 0.81 (0.64-1.20)

• G3 = 0.84 (0.57-1.25)

Hsia et al 2005 [118] USA

To evaluate the relationship between PA and the incidence of T2D in a large, diverse group of older women.

• n = 87,907

PA assessment: Questionnaire for frequency and duration of 4 walking speeds and 3 other activities classified by intensity (light, moderate, strenuous)

Number of cases: 2,271

There is a strong inverse relationship between PA and T2D. There is a stronger relationship between PA and T2D in Caucasian women than in minority women. This may be explained by less precise risk estimates in minority women.

• Sex: Women

• Age: White 63.8 ± 7.3, African American 61.9 ± 7.3, Hispanic 60.5 ± 7.1, Asian/Pacific Islander 63.7 ± 7.6, American Indian 61.5 ± 8.0

Multivariate adjusted HR (95% CI) by walking, Caucasian

• Q1 = 1.00 (referent)

Prospective cohort

• Q2 = 0.85 (0.74-0.87)

• Q3 = 0.87 (0.75-1.01)

• Q4 = 0.75 (0.64-0.89)

D & B score = 11

Q1 = Low

• Q5 = 0.74, (0.62-0.89)

Q2 =

Trend p < 0.001

Q3 =

Q4 =

Multivariate adjusted HR (95% CI) by TPA, Caucasian

Q5 = High

• Ethnicity: White n = 74,240; African American n = 6,465; Hispanic n = 3,231; Asian/Pacific Islander 2,445; American Indian n = 327

• Q1 = 1.00 (referent)

Cox proportional HR

• Q2 = 0.88 (0.76- 1.01)

• Q3 = 0.74 (0.64- 0.87)

• Q4 = 0.80 (0.68- 0.94)

• Q5 = 0.67 (0.56- 0.81) Trend p = 0.002

• Characteristics: participants had no history of diabetes, were not on any antidiabetic medications

• Women's Health Initiative

Wannamethee et al 2000 [120]

To examine the role of components of the insulin resistance syndrome in the relationship between PA and the incidence of T2D and CHD.

• n = 5,159

16.8 yr follow-up

Number of cases: 196

The relationship between PA and T2D appears to be mediated by serum insulin and components of the insulin resistance syndrome. However, these factors do not appear to explain the inverse relationship between PA and T2D.

• Sex: Men

• Age: 40-59 yr

PA assessment: Questionnaire for TPA Physical activity groups were identified and scored:

Multivariate adjusted RR (95% CI)

England, Wales and Scotland

• Characteristics: No history of heart disease, diabetes or stroke

   Q1 = 1.00 (referent)

   Q2 = 0.66 (0.42-1.02)

   Q3 = 0.65 (0.41-1.03)

Prospective cohort

   Q4 = 0.48 (0.28-0.83)

Q1 = None

   Q5 = 0.46 (0.27-0.79)

Q2 = Occasional

p < 0.005

D & B score = 14

Q3 = Light

Q4 = Moderate

Q5 = Moderately vigorous/vigorous

MPA (sporting activity once a week or frequent lighter- intensity activities such as walking, gardening, do-it yourself projects) are sufficient to produce a significant reduction in risk of both CHD and T2D.

The men were classified according to current smoking status, alcohol consumption, and social class

Cox proportional HR

Manson et al 1991 [121]

To examine the association between regular VPA and the incidence of T2D.

• n = 87,253

8 yr follow-up

Number of cases: 1303 Women who engage in VPA at least once per week had reduced adjusted RR of T2D RR = 0.66 (0.6- 0.75)

PA is promising in the primary prevention of T2D.

• Sex: Women

• Age: 34-59 yr

PA assessment:

USA

• Characteristics: Free of diagnosed diabetes, cardiovascular disease and cancer

Questionnaire

Frequency of weekly exercise (0-+4)

Prospective cohort

The reduction in risk remained significant after adjustment for BMI RR = 0.84 (0.75-0.95)

D & B score = 13

Analysis also restricted to the first 2 yr after the assessment of PA level and to symptomatic diabetes

When analysis was restricted to the first 2 years after ascertainment of PA level and to symptomatic disease as the outcome, the age- adjusted RR of those who exercised was 0.50, and age and body-mass index adjusted RR was 0.69 (0.48-1.0)

Multivariate adjustments for age, body-mass index, family history of diabetes, and other variables did not alter the reduced risk found with exercise

Multivariate analysis

Family history of diabetes did not modify the effect of exercise, and risk reduction with exercise was evident among both obese and non-obese women

Helmrich et al 1994 [122]

To examine the relationship between PA and the development of T2D.

• n = 5,990

98,524 man-years of follow-up (1962-1976)

Number of cases: 202

Increased PA is effective in preventing T2D.

• Sex: Men

• Age: 39-68 yr

RR (95% CI) by blocks walked per day

USA

• Characteristics: healthy, asymptomatic

PA assessment: Questionnaire for LTPA (walking, stair climbing, sports etc; kcal/wk) Blocks walked/day

The protective benefit is especially pronounced in those individuals who have the highest risk of disease.

   • T1 = 1.00 (referent)

Further review of the data reported by Helmich et al. 1991

   • T2 = 1.30

University of Pennsylvania Alumni Health Study

   • T3 = 0.92

p = 0.80

LTPA (kcal/wk) kcal were assigned to each activity and added together

LTPA was inversely related to the development of T2D

Prospective cohort

Same findings to that reported in 1991

D & B score = 14

Lowest < 500

Highest ≥ 3500

Blocks walked/day

T1 = <5

T2 = 5-14

T3 = ≥15

Cox proportional HR

Helmrich et al 1991 [123]

To examine the Relationship between PA and the Subsequent development of T2D.

• n = 5,990

98,524 man-years of follow-up (1962-1976)

Number of cases: 202

Increased PA is effective in preventing T2D.

• Sex: Men

• Age: 39-68 yr

LTPA was inversely related to the development of type 2 diabetes

USA

• Characteristics: healthy, asymptomatic

PA assessment: Questionnaire for LTPA kcal/wk: stairs climbed/day and blocks walked/day, divided into groups

The protective benefit is especially pronounced in those individuals who have the highest risk of disease.

Prospective cohort

RR (95% CI) by sports played

• University of Pennsylvania Alumni Health Study

• G1 = 1.00 (referent)

• G2 = 0.90

D & B score = 13

• G3 = 0.69

• G4 = 0.65

All activities LTPA

Trend p = 0.02

Q1 = <500

Q2 = 500-999

RR (95% CI) by Flights of stairs climbed/day

Q3 = 1000-1499

Q4 = 1500-1999

• T1 = <5 = 1.00 (referent)

Q5 = 2000-2499

• T2 = 0.78

Q6 = 2500-2999

• T3 = 0.75

Q7 = 3000-3499

Trend p = 0.07

Q8 = ≥ 3500

RR (95% CI) by Blocks walked/day

Sports played

• T1 = 1.00 (referent0

G1 = None

• T2 = 1.31

G2 = Moderate

G3 = Vigorous

• T3 = 0.93

Trend p = 0.80

G4 = Moderate and Vigorous

Age adjusted RR (95% CI) by all activities

Stairs climbed per day

T1 = <5

• Q1 = 1.00 (referent)

T2 = 5-14

• Q2 = 0.94

T3 = ≥ 15

• Q3 = 0.79

• Q4 = 0.78

Blocks walked per day

• Q5 = 0.68

T1 = <5

• Q6 = 0.90

T2 = 5-14

• Q7 = 0.86

T3 = ≥ 15

• Q8 = 0.52

p = 0.01 for trend

Cox proportional HR

Age adjusted RR (95% CI) by all activities except vigorous sports

• Q1 = 1.00 (referent)

• Q2 = 0.97

• Q3 = 0.87

• Q4 = 0.92

• Q5 = 0.75

• Q6 = 1.29

• Q7 = 1.03

• Q8 = 0.48

Trend p = 0.07

Age adjusted RR (95% CI) by vigorous sports only

• Q1 = 1.00 (referent)

• Q2 = 0.69

• Q3 = N/A

• Q4 = 0.53

• Q5 = 0.86

• Q6 = 0.56

• Q7 = 0.40

• Q8 = 0.46

Trend p = 0.05

Wei et al 1999 [124]

To determine whether PF is associated with risk for impaired fasting glucose and T2D.

• n = 8,633

6 yr follow-up

Number of cases: 149

High PF is associated with a reduced risk for impaired fasting glucose and T2D.

USA

• Sex: Men

• Age: 43.5 yr

PF assessment: Maximal treadmill exercise test (METs), divided into 3 groups

593 patients developed impaired fasting glucose

• Characteristics: Non-diabetic men

OR (95% CI) for developing glucose intolerance

Prospective cohort

T1 = Low

• T1 = 1.9 (1.5--2.4)

T2 = Moderate

• T2 = 1.5 (1.2--1.8)

T3 = High

• T3 = 1.00 (referent)

D & B score = 12

Outcome measure: Incidence of impaired fasting glucose and T2D

OR (95% CI) for developing T2D

• T1 = 3.7 (2.4 --5.8)

• T2 = 1.7 (1.1--2.7)

• T3 = 1.00 (referent)

Statistics: GLM

Katzmarzyk et al 2007 [126]

To examine the relationships among adiposity, PA, PF and the development of T2D in a diverse sample of Canadians.

• n = 1,543 (709 men and 834 women)

6 yr follow-up

Number of cases: 78 (37 in men, 41 in women)

Adiposity and PF are important predictors of the development of T2D.

Canada

• Sex: Men and women

PF assessment: Questionnaire

PA was associated with 23% lower odds of developing diabetes and maximal METs was also associated with significantly lower odds of developing diabetes (OR = 0.28)

Prospective cohort

• Age: 36.8 - 37.5

PA assessment: LTPA Questionnaire

D & B score = 13

• Characteristics: Free of diabetes at baseline

• Canadian Physical Activity Longitudinal Study

Burchfiel et al 1995 [345]

To examine the relationship between PA and T2D.

• n = 6,815

6 yr follow-up

Number of cases: 391

PA is associated inversely and independently with incident T2D.

USA

• Sex: Men (Japanese- American)

PA assessment: Questionnaire PA index (based on intensity and duration of activity)

The age-adjusted 6-year cumulative incidence of diabetes decreased progressively with increasing quintile of physical activity from 73.8 to 34.3 per 1,000 (p < 0.0001, trend)

• Age: 45-68 yr

Levels of activity:

Prospective cohort

• Characteristics: Free of diabetes at entry

Q1 = Basal - Sleeping reclining

D & B score = 13

• The Honolulu Heart Program

Q2 = Sedentary

Q3 = Slight - Casual walking

Q4 = Moderate -- Gardening

Q5 = Heavy - Lifting, shoveling

Outcome measure: Self-reported T2D (clinically recognized)

Dziura et al 2004 [346]

To determine the prospective relation between reports of habitual PA, 3-year change in body weight, and the subsequent risk of T2D in an older cohort.

• n = 2,135

PA assessment: Questionnaire for 4 types of activities (walking, gardening/housework, physical exercises, active sports or swimming) and frequency of participation measured with a PA score:

118 cases of T2D

Observation of an inverse relationship between reported PA and rate of T2DM.

USA

• Sex: Men and women

Incident density of T2D = 6.6/1000 person years

• Age: ≥ 65 yr

Prospective cohort

• Ethnicity: 83% White, 15% African American, 2% Non-white

Diabetes (n = 118) PA score: 2.17 ± 1.7 'Some' PA: 78%

Subjects reporting some PA at baseline experienced a rate of T2D over 50% lower relative to those reporting no PA.

D & B score = 12

• Characteristics: Healthy asymptomatic

Never (score 0) Sometimes (score 1) Often (score 2)

Non-Diabetes (n = 2017) PA score: 2.34 ± 1.7 'Some' PA: 84%

Pearson product moment correlation coefficient and Cox proportional HR

Hu et al. 1999 [347]

To quantify the dose-response relationship between total PA and incidence of T2D in women.

• n = 70,102

8 yr of follow-up

Number of cases: 1419

Increased PA is associated with substantial reduction in risk of T2D including PA of moderate intensity and duration.

USA

• Sex: Women

PA assessment: Questionnaire for TPA (MET hr/wk) and VPA (6 METs)

Multivariate-adjusted RR (95% CI) of by TPA

• Age: 40-65 yr

• Q1 = 1.0 (referent)

Prospective cohort

To examine the health benefits of walking in comparison to more vigorous activity.

• Characteristics: participants had no history of diabetes, CVD, or cancer

TPA (MET hr/wk)

• Q2 = 0.77 (0.66-0.90)

D & B score = 12

Nurses' Health Study

Q1 = 0-2.0

• Q3 = 0.75 (0.65-0.88)

Q2 = 2.1-4.6

• Q4 = 0.62 (0.52-0.73)

Q3 = 4.7-10.4

• Q5 = 0.54 (0.45-0.64)

Q4 = 10.5-21.7

Trend p < 0.001

• Q5 = ≥ 21.8

MET score

Multivariate-adjusted RR (95% CI) among women who did not perform vigorous exercise (MET's):

Q1 = ≤ 0.5

• Q1 = 1.0 (referent)

Q2 = 0.6-2.0

• Q2 = 0.91 (0.75-1.09)

Q3 = 2.1-3.8

• Q3 = 0.73 (0.59-0.90)

Q4 = 3.9-9.9

• Q4 = 0.69 (0.56-0.86)

Q5 = ≥ 10.0

• Q5 = 0.58 (0.46-0.73)

Outcome measures:

Trend p < 0.001

Incidence of T2D

Hu et al 2001 [348]

To examine the role of prolonged television watching on the risk for T2D.

• n = 37,918

10 year follow-up

Number of cases: 1058

Increasing PA is associated with a significant reduction in risk for T2D, whereas a sedentary lifestyle indicated by prolonged TV watching is related directly to increased risk.

USA

• Sex: Men

• Age: 40-75 yr

PA assessment: Questionnaire for PA (MET hr/wk) and TV watching (h/wk), each divided into quintiles

Multivariate-adjusted RR (95% CI) by PA

Prospective cohort

• Characteristics: participants had no history of diabetes, CVD, or cancer

Q1 = 0-5.9

• Q1 = 1.00 (referent)

D & B score = 11

• Health Professionals' Follow-up Study

Q2 = 6.0-13.7

• Q2 = 0.78 (0.66 -- 0.93)

Q3 = 13.8-24.2

• Q3 = 0.65 (0.54 -- 0.78)

Q4 = 24.3-40.8

• Q4 = 0.58 (0.48 -- 0.70)

Q5 = ≥ 40.9

• Q5 = 0.51 (0.41 -- 0.63)

Trend p < 0.001

Time spent watching television per week (h/wk)

Multivariate-adjusted RR (95% CI) by TV time

Q1 = 0-1

• Q1 = 1.00 (referent)

Q2 = 2-10

• Q2 = 1.66 (1.15 - 2.39)

Q3 = 11-20

• Q3 = 1.64 (1.12 - 2.41)

Q4 = 21-40

• Q4 = 2.16 (1.45 - 3.22)

Q5 = >40

• Q5 = 2.87 (1.46 - 5.65)

Trend p < 0.001

Rana et al 2007 [349]

To examine the individual and combined association of obesity and physical inactivity with the incidence of T2D.

• n = 68,907

16 yr follow-up

Number of cases: 4,030

This study found that obesity and physical inactivity independently contributed to the development of T2D.

USA

• Sex: Women

Prospective cohort

• Age: 30-55 years age range in 1976 (note: 1986 was the baseline year for the study)

PA assessment: Questionnaire for average amount of time/week MET hours per week spent in MVPA (≥ 3 METs), divided into quintiles

Multivariate-adjusted RR (95% CI) by MVPA:

The benefits of PA were not limited to lean women; among those who were overweight and obese, physically active women tended tobe at lower risk for T2D than sedentary women.

D & B score = 12

• Characteristics: No history of diabetes, CVD or cancer

Q1 = <2.1

• Q1 = 2.37 (2.15--2.16)

• Nurses' Health Study

Q2 = 2.1-4.6

• Q2 = 1.92 (1.73--2.13)

Q3 = 4.7-10.4

• Q3 = 1.48 (1.34--1.64)

Q4 = 10.5-21.7

• Q4 = 1.40 (1.26--1.55)

Q5 = ≥ 21.8

• Q5 = 1.00 (referent)

Trend p < 0.001

Cox proportional HR

Sawada et al 2003 [350]

To examine the association between PF and the incidence of T2D.

• n = 4,747

14 yr follow-up

Number of cases: 280

Low PF is associated with a higher risk for the development of T2D.

Japan

• Sex: Men

• Age: 20-40 yr

PF assessment: Maximal aerobic power estimate ml/kg/min using a submaximal cycle ergometer test, divided into quartiles

Age-adjusted RR (95% CI)

Prospective cohort

• Characteristics: Free of diabetes, CVD, hypertensin, tuberculosis, and gastrointestinal disease at baseline

Q1 = 32.4 ± 3.1

• Q1 = 1.00 (referent)

D & B score = 13

Q2 = 38.0 ± 2.5

• Q2 = 0.56 (0.42-- 0.75)

Q3 = 42.4 ± 3.0

• Q3 = 0.35 (0.25-- 0.50)

Q4 = 51.1 ± 6.2

• Q4 = 0.25 (0.17-- 0.37)

Trend p < 0.001

Outcome measure: Incidence of T2D

Multivariate adjusted RR (95% CI)

• Q1 = 1.00 (referent)

• Q2 = 0.78 (0.58--1.05)

• Q3 = 0.63 (0.45--0.89)

• Q4 = 0.56 (0.37--0.84)

Trend p = 0.001

Cox proportional HR

Weinstein et al 2004 [351]

To examine the relative contributions and joint association of PA and BMI with T2D.

• n = 37,878

6.9 year follow up

Number of cases: 1,361

Although BMI and physical inactivity are independent predictors of incident diabetes, the magnitude of the association with BMI was greater than with PA in combined analyses. These findings underscore the critical importance of adiposity as a determinant of T2D.

USA

• Sex: Women

PA assessment: Questionnaire for walking per week (h/wk) and TPA (kcal/wk), divided into groups and quartiles respectively

Multivariate-adjusted HR (95% CI) by time spent walking

• Age: 45+ years

• G1 = 1.00 (referent)

Prospective cohort

• Health care professionals

• G2 = 0.95 (0.82-1.10)

D & B score = 12

• Characteristics: No history of CVD, cancer or diabetes

• G3 = 0.87 (0.73 -1.02)

• G4 = 0.66 (0.54-0.81)

• G5 = 0.89 (0.73-1.09)

Walking per week (h/wk)

Trend p = 0.004

G1 = no walking

Multivariate-adjusted HR (95% CI) by TPA

G2 = <1

• Q1 = 1.00 (referent)

G3 = 1-1.5

• Q2 = 0.91 (0.79-1.06)

G4 = 2-3

• Q3 = 0.86 (0.74-1.01)

G5 = ≥ 4

• Q4 = 0.82 (0.70-0.97)

TPA (kcal/wk)

Trend p = 0.01

Q1 < 200

Q2 = 200-599

Q3 = 600-1,499

Q4 ≥ 1500

Cox proportional HR