Table 2—

Multivariate adjusted geometric mean HOMA-IR and prevalence OR of metabolic syndrome across quintiles of carbohydrate-related dietary factors

Quintiles of carbohydrate source§
P for trend
Quintile 1Quintile 2Quintile 3Quintile 4Quintile 5
n566567567567567
Total carbohydrate
  Median intake (g/day)179207226244272
  Range of intake (g/day)<194195–217218–234235–257>258
  Mean HOMA-IR*6.8 (6.5–7.1)6.7 (6.5–7.0)6.6 (6.3–6.8)6.7 (6.5–7.0)6.9 (6.6–7.2)0.52
  OR IRS1.000.90 (0.65–1.23)0.76 (0.53–1.09)1.03 (0.69–1.52)0.92 (0.57–1.49)0.97
Dietary fiber
  Median intake (g/day)11.614.917.420.125.5
  Range of intake (g/day)<13.513.6–16.016.1–18.618.6–22.1>22.2
  Mean HOMA-IR7.0 (6.8–7.3)6.7 (6.5–7.0)6.7 (6.5–7.0)6.7 (6.5–7.0)6.4 (6.1–6.6)<0.001
  OR IRS1.00.81 (0.61–1.09)0.88 (0.65–1.19)0.81 (0.59–1.07)0.73 (0.51–1.03)0.11
Cereal fiber
  Median intake (g/day)2.63.74.65.88.0
  Range of intake (g/day)<3.13.2–4.24.3–5.15.2–6.7>6.8
  Mean HOMA-IR6.8 (6.5–7.0)6.9 (6.7–7.2)6.8 (6.6–7.0)6.6 (6.4–6.9)6.5 (6.3–6.8)0.02
  OR IRS1.00.87 (0.65–1.16)0.88 (0.66–1.18)0.74 (0.54–1.00)0.62 (0.45–0.86)0.002
Fruit fiber
  Median intake (g/day)0.71.72.84.25.8
  Range of intake (g/day)<1.21.2–2.22.2–3.43.4–5.1>5.2
  Mean HOMA-IR7.0 (6.7–7.2)6.8 (6.5–7.0)6.8 (6.5–7.0)6.6 (6.4–6.8)6.5 (6.2–6.7)<0.001
  OR IRS1.01.07 (0.80–1.43)0.74 (0.55–1.01)0.89 (0.65–1.21)0.88 (0.64–1.22)0.36
Vegetable fiber
  Median intake (g/day)2.43.74.86.18.4
  Range of intake (g/day)<3.13.1–4.24.2–5.35.3–6.9>6.9
  Mean HOMA-IR6.7 (6.4–6.9)6.9 (6.6–7.2)6.7 (6.4–6.9)6.8 (6.5–7.0)6.8 (6.5–7.0)0.64
  OR IRS1.01.08 (0.81–1.45)1.04 (0.77–1.40)1.00 (0.74–1.36)1.15 (0.84–1.57)0.51
Legume fiber
  Median intake (g/day)0.230.691.01.42.5
  Range of intake (g/day)<0.50.6–0.80.8–1.21.2–1.8>1.8
  Mean HOMA-IR6.8 (6.5–7.0)6.8 (6.6–7.1)6.8 (6.5–7.0)6.7 (6.5–6.9)6.7 (6.5–7.0)0.58
  OR IRS1.000.91 (0.68–1.23)0.90 (0.67–1.20)1.00 (0.75–1.34)0.96 (0.72–1.29)0.98
Glycemic index
  Median intake (per day)7276788184
  Range of intake (per day)<7474–7777–7979–8282–98
  Mean HOMA-IR6.4 (6.2–6.7)6.7 (6.5–7.0)6.8 (6.5–7.0)6.8 (6.5–7.0)7.0 (6.7–7.2)<0.001
  OR IRS1.001.17 (0.86–1.59)1.21 (0.89–1.64)1.19 (0.88–1.62)1.41 (1.04–1.91)0.04
Glycemic load
  Median intake (g/day)131158.6174.5190.8220.3
  Range of intake (g/day)<147.0147.1–166.3166.4–182.3182.3–202.1>202.2
  Mean HOMA-IR6.7 (6.4–7.0)6.5 (6.2–6.7)6.7 (6.5–7.0)6.8 (6.6–7.1)7.0 (6.7–7.3)0.03
  OR IRS1.000.74 (0.53–1.02)0.71 (0.50–1.00)1.00 (0.69–1.46)0.82 (0.52–1.27)0.74
Whole grains
  Median intake (serving/week)0.903.56.49.520.4
  Range of intake (serving/week)<1.51.9–4.44.5–7.57.9–12.9>13
  Mean HOMA-IR6.8 (6.6–7.1)6.9 (6.6–7.1)6.7 (6.5–7.0)6.6 (6.4–6.8)6.6 (6.4–6.9)0.05
  OR IRS1.00.81 (0.60–1.08)1.09 (0.82–1.44)0.82 (0.61–1.10)0.67 (0.48–0.91)0.01
Refined grains
  Median intake (serving/week)6.911.916.723.738.8
  Range of intake (serving/week)<9.79.7–13.914.0–19.819.9–29.3>29.3
  Mean HOMA-IR6.8 (6.6–7.1)6.6 (6.4–6.9)6.8 (6.6–7.1)6.8 (6.5–7.0)6.7 (6.5–7.0)0.81
  OR IRS1.01.13 (0.84–1.52)1.01 (0.74–1.38)1.03 (0.75–1.42)0.76 (0.53–1.09)0.05
  • *

    * Geometric mean HOMA-IR adjusted for sex, age, BMI, waist-to-hip ratio, cigarette dose, total energy intake, alcohol intake, percentage saturated fat, percentage polyunsaturated fat, multivitamin use, physical activity, and treatment for blood pressure. Results were essentially the same when the analysis was repeated using fasting insulin rather than the HOMA-IR.

  • Adjusted for sex, age, cigarette dose, total energy intake, alcohol intake, percentage saturated fat, percentage polyunsaturated fat, multivitamin use, and physical activity.

  • Values are based on a white bread standard.

  • §

    § Quintile categories are based on energy-adjusted values using the residual method, with the exception of whole and refined grains. IRS, insulin resistance syndrome.