Table 2 Characteristics of studies included in the meta-analysis

Moore et al. [23]

2014

USA

Cohort

Colon cancer

55 to 69

Both

Total (147/3763)

MHNW (36\1356)

MUHNW (3\172)

MHO (94\1911)

MUHO (14\324)

Metabolically unhealthy phenotype was defined as having elevated blood glucose (> 125 mg/dL)

Normal weight: BMI < 25 kg/m2

Obese: BMI ≥25 kg/m2

1948 to 1970

Adjusted for age, sex, height, education level, alcohol, cigarettes/day, and physical activity plus waist circumference.

Liang et al. [22]

2017

USA

Cohort

Colorectal cancer

66.7 ± 6.9

Female

Total (114/5068)

MHNW (64\3358)

MUHNW (50\1710)

Presence of metabolic syndrome Based on the criteria of the Adult Treatment Panel III

Normal weight: BMI 18.5 to < 25 kg/m2

1993 to 2015

adjusted for age, ethnicity, smoking, alcohol consumption, physical activity, total energy intake, dietary fiber, percent calories from fat, family history of colorectal cancer, NSAIDs use, and treatment

Murphy et al. [25]

2016

UK

Cohort

Colorectal cancer

57.6 ± 6.4

Both

Total (1474)

MHNW (101/232)

MUHNW (158/291)

MHO (93/214)

MUHO (385/737)

Based on the distribution of C-peptide concentration amongst the control population, and participants were classified as metabolically healthy if below the first tertile of C-peptide and metabolically unhealthy if above the first tertile.

Normal weight: BMI < 25 kg/m2

Obese: BMI ≥25 kg/m2

1992 and 2000

was conditioned on matching factors, with additional adjustment for height, smoking status, physicalactivity,educationlevel,alcoholconsumption,anddietaryintakesoftotalenergy,redandprocessedmeats,andfibre

Shin et al. [24]

2017

Korea

Cohort

Colorectal cancer

NR

Male

Total (2951/183,921)

MHNW (830\ 94,885)

MUHNW (1000\38,218)

MHO (362\ 21,828)

MUHO (759\28,990)

Those with none of the three metabolic disease components were considered metabolically healthy

Normal weight: BMI < 25 kg/m2

Obese: BMI ≥25 kg/m2

9 years

Adjusted for age and sex, smoking, drinking, exercise, and income.

Female

Total (2009/225,010)

MHNW (700\100,341)

MUHNW (597\50,404)

MHO (228\34,601)

MUHO (484\39,664)

Kabat et al. [13]

2018

USA

Cohort

Colorectal cancer

62.3 ± 7.2

Female

Total (311/13,535)

MHNW (111\4612)

MUHNW (20\563)

MHO (70\3419)

MUHO (110\4941)

Presence of metabolic syndrome Based on the criteria of the Adult Treatment Panel III

Normal weight: BMI 18.5 to 25 kg/m2

Obese: BMI ≥30 kg/m2

1993 and 1998

Adjusted for age, smoking status, alcohol intake, physical activity, aspirin intake, dietary calcium intake, dietary folate intake, caloric intake, oral contraceptives, hormone therapy, family history of colorectal cancer in first-degree relative, education, ethnicity

Cao et al. [20]

2020

UK

Cohort

Colorectal cancer

56.3 ± 8.1

Both

Total (NR/223,030)

MHNW (NR/90510)

MUHNW (NR/36347)

MHO (NR/26094)

MUHO (NR/70079)

Presence of metabolic syndrome Based on the criteria of the Adult Treatment Panel III

Normal weight: BMI 18.5 to 25 kg/m2

Obese: BMI ≥30 kg/m2

2006 t0 2016

Adjusted for sex, age, ethnicity, Townsend deprivation index, qualification, employment status, alcohol intaking, smoking status, hormone therapy use, oral contraceptive use and menopause after excluded females with history of hysterectomy.

Cho et al. [21]

2020

Korea

Cohort

Colorectal cancer

57.5 ± 8.0

Male

Total (4136/166,925)

MHNW (935/44,194)

MUHNW (1625/60,416)

MHO (314\13,824)

MUHO (1262\48,536)

Presence of metabolic syndrome Based on the criteria of the Adult Treatment Panel III

Normal weight: BMI 18.5 to 25 kg/m2

Obese: BMI ≥30 kg/m2

2009 to 2015

Adjusted for baseline age, income, smoking, alcohol drinking, and presence of inflammatory bowel disease

Female

Total (2727/152,427)

MHNW (708\49,383)

MUHNW (1019\50,609)

MHO (253\14,733)

MUHO (747\37,702)