Carbohydrate Nutrition, Insulin Resistance, and the Prevalence of the Metabolic Syndrome in the Framingham Offspring Cohort
Article Figures & Tables
Tables
- Table 1—
Characteristics of subjects in the Framingham Offspring Cohort across quintile categories of HOMA-IR insulin resistance
HOMA-IR Quintile categories P value* <4.83 4.84–5.71 5.72–6.79 6.79–8.64 >8.64 Participants (n) 568 565 567 568 565 Characteristics Women (%) 71 64 51 46 41 <0.0001 Age (years) 52 53 54 55 56 <0.0001 BMI (kg/m2) 24.2 25.4 26.6 28.4 31.3 <0.0001 Physical activity score 34.6 34.7 34.8 35.2 34.5 0.74 Alcohol use (%) 78 75 76 73 67 <0.0001 Current cigarette smoking (%) 21 20 19 20 16 0.07 Estrogen replacement therapy (women only) (%) 18 21 18 14 9 <0.001 Normal glucose tolerance (%)† 94 91 90 77 50 <0.0001 Impaired fasting glucose/impaired glucose tolerance (%)† 6 8 9 20 33 <0.0001 Undiagnosed diabetes (%)† 0 1 1 3 17 <0.0001 Fasting serum insulin (μU/ml) 1.9 4.3 6.8 10.0 19.3 <0.0001 Insulin resistance phenotype Abnormal waist circumference (%)‡ 13 25 31 50 72 <0.0001 Low HDL cholesterol (%)§ 19 24 35 45 64 <0.0001 Elevated triglycerides (%)‖ 12 19 29 41 61 <0.0001 Elevated fasting glucose (%)¶ 0 2 2 11 38 <0.0001 Abnormal blood pressure (%)# 10 14 18 29 42 <0.0001 Metabolic syndrome ≥3 components (%) 2 7 11 28 59 <0.0001 Data are means unless otherwise indicated. Geometric means are given for levels of fasting insulin.
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↵* P values for trend for continuous variables or Mantel-Haenzel χ2 for categorical variables across quintiles of HOMA-IR.
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↵† Previously undiagnosed diabetes was defined as a fasting plasma glucose concentration ≥126 mg/dl (7.0 mmol/l) or a 2-h postchallenge glucose concentration ≥200 mg/dl (11.1 mmol/l). Impaired fasting glucose was defined as a fasting plasma glucose concentration of 110–126 mg/dl (6.1–7.0 mmol/l). Impaired glucose tolerance was defined as a 2-h postchallenge glucose concentration of 140–200 mg/dl (11.1 mmol/l). Normal glucose tolerance was defined as a fasting glucose concentration of <110 mg/dl (6.1 mmol/l) and a 2-h postchallange glucose concentration of <140 mg/dl (7.8 mmol/l).
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↵‡ Waist circumference >40 inches in men and >35 inches in women.
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↵§ Serum HDL cholesterol <40 mg/dl or <50 mg/dl in men and women, respectively.
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↵‖ Triglyceride level ≥150 mg/dl.
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↵# Blood pressure of at least 130/85 mmHg or taking hypertensive medication.
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↵¶ Fasting plasma glucose concentration ≥6.1 mmol/l.
- 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 1 Quintile 2 Quintile 3 Quintile 4 Quintile 5 n 566 567 567 567 567 Total carbohydrate Median intake (g/day) 179 207 226 244 272 Range of intake (g/day) <194 195–217 218–234 235–257 >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 IRS† 1.00 0.90 (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) 11.6 14.9 17.4 20.1 25.5 Range of intake (g/day) <13.5 13.6–16.0 16.1–18.6 18.6–22.1 >22.2 Mean HOMA-IR 7.0 (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 IRS 1.0 0.81 (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) 2.6 3.7 4.6 5.8 8.0 Range of intake (g/day) <3.1 3.2–4.2 4.3–5.1 5.2–6.7 >6.8 Mean HOMA-IR 6.8 (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 IRS 1.0 0.87 (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) 0.7 1.7 2.8 4.2 5.8 Range of intake (g/day) <1.2 1.2–2.2 2.2–3.4 3.4–5.1 >5.2 Mean HOMA-IR 7.0 (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 IRS 1.0 1.07 (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) 2.4 3.7 4.8 6.1 8.4 Range of intake (g/day) <3.1 3.1–4.2 4.2–5.3 5.3–6.9 >6.9 Mean HOMA-IR 6.7 (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 IRS 1.0 1.08 (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) 0.23 0.69 1.0 1.4 2.5 Range of intake (g/day) <0.5 0.6–0.8 0.8–1.2 1.2–1.8 >1.8 Mean HOMA-IR 6.8 (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 IRS 1.00 0.91 (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) 72 76 78 81 84 Range of intake (per day) <74 74–77 77–79 79–82 82–98 Mean HOMA-IR 6.4 (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 IRS 1.00 1.17 (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) 131 158.6 174.5 190.8 220.3 Range of intake (g/day) <147.0 147.1–166.3 166.4–182.3 182.3–202.1 >202.2 Mean HOMA-IR 6.7 (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 IRS 1.00 0.74 (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) 0.90 3.5 6.4 9.5 20.4 Range of intake (serving/week) <1.5 1.9–4.4 4.5–7.5 7.9–12.9 >13 Mean HOMA-IR 6.8 (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 IRS 1.0 0.81 (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) 6.9 11.9 16.7 23.7 38.8 Range of intake (serving/week) <9.7 9.7–13.9 14.0–19.8 19.9–29.3 >29.3 Mean HOMA-IR 6.8 (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 IRS 1.0 1.13 (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.
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↵† Adjusted for sex, age, cigarette dose, total energy intake, alcohol intake, percentage saturated fat, percentage polyunsaturated fat, multivitamin use, and physical activity.
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↵‡ Values are based on a white bread standard.
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↵§ Quintile categories are based on energy-adjusted values using the residual method, with the exception of whole and refined grains. IRS, insulin resistance syndrome.
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