Lau C, Færch K, Glümer C, Tetens I, Pedersen O, Carstensen B, Jørgensen T, Borch-Johnsen K: Dietary glycemic index, glycemic load, fiber, simple sugars, and insulin resistance: the Inter99 study. Diabetes Care 28:1397–1403, 2005
The authors of the above-listed article discovered a coding error in their dietary data. Although this error does not affect their original conclusion, the following alterations are required.
In Table 1, the absolute and relative numbers have changed, and for sucrose, the P value is no longer significant (P = 0.051).
In Table 2, the estimates and 95% CIs for glycemic index, carbohydrate, sucrose, fructose, and lactose are only marginally changed, whereas all other estimates have remained the same. The P value has changed for several variables, but the level of significance was only affected for two of the variables. Glycemic load and carbohydrate are therefore no longer significantly inversely associated with HOMA-IR in the adjusted analysis.
In the final paragraph of the results, the correlation between glycemic load and carbohydrate changes marginally (σ2 = 0.97821 instead of 0.97799). Adjustment for dietary fiber just affects the associations between glycemic load or carbohydrate and HOMA-IR towards more insignificance. (This should also be noted in the results section of the abstract.) It still attenuates the level of significance for the association between fruits/vegetables and HOMA-IR.
On p. 1401, at the beginning of the fifth paragraph of the conclusions, the authors have deleted the following text: “Any change in the carbohydrate composition of the diet will produce reciprocal changes in other parts of the diet. A concomitant decrease in fat consumption may therefore explain the inverse association between total carbohydrate intake and insulin resistance observed from the multiple regression analysis, as well as it explains findings from other studies (11).”
In the second from last paragraph of the conclusions, the authors have deleted the following sentence: “Intake of dietary fiber explained the observed inverse associations with daily glycemic load and carbohydrates and attenuated the association with fruit and vegetables.” Also, they have changed the beginning of the next sentence from “These data are consistent… ” to “Findings from this study are consistent… ”
Characteristics of 5,675 nondiabetic subjects in the Inter99 study group into quartiles of HOMA-IR
| . | Quartiles . | . | . | . | . | |||
|---|---|---|---|---|---|---|---|---|
| . | 0.12 to <0.79 . | 0.79 to <1.15 . | 1.15 to <1.76 . | 1.76 to 14.74 . | P* . | |||
| Participants (n) | 1,425 | 1,418 | 1,421 | 1,411 | ||||
| Men (%) | 41.7 | 45.9 | 47.9 | 57.8 | 0.000 | |||
| Physically inactive (%) | 29.6 | 30.1 | 37.8 | 40.2 | 0.000 | |||
| Smokers (%) | 47.3 | 42.5 | 37.0 | 30.5 | 0.000 | |||
| Normal glucose tolerant (%)† | 91.0 | 85.8 | 80.0 | 58.8 | 0.000 | |||
| Impaired fasting glucose (%)† | 1.8 | 6.1 | 9.9 | 17.7 | 0.000 | |||
| Impaired glucose tolerant (%)† | 7.2 | 8.1 | 10.2 | 23.5 | 0.000 | |||
| Age (years) | 45.1 (40.0–50.1) | 45.0 (39.9–50.2) | 45.0 (40.0–50.2) | 45.1 (40.0–50.3) | 0.067 | |||
| BMI (kg/m2) | 23.3 (21.5–25.2) | 24.7 (22.8–26.8) | 26.1 (23.9–28.5) | 28.9 (26.0–32.2) | 0.000 | |||
| Waist (cm) | 78.0 (71.0–86.0) | 83.0 (75.0–91.0) | 87.0 (78.0–95.0) | 95.0 (87.0–104.0) | 0.000 | |||
| Energy (kcal) | 2,320 (1,965–3,042) | 2,270 (1,873–2,983) | 2,286 (1,925–3,037) | 2,282 (1,918–2,976) | 0.000 | |||
| Fat (E%) | 32.0 (27.5–39.0) | 32.7 (28.3–39.7) | 32.8 (28.0–40.2) | 32.3 (28.2–40.2) | 0.185 | |||
| Protein (E%) | 13.3 (12.7–16.3) | 13.6 (12.8–16.4) | 13.7 (12.8–16.4) | 13.8 (12.9–16.7) | 0.000 | |||
| Alcohol (E%) | 3.2 (1.1–6.5) | 2.9 (1.0–5.5) | 2.7 (0.9–5.4) | 2.7 (0.8–5.7) | 0.000 | |||
| Carbohydrate (E%) | 49.2 (40.7–53.1) | 48.8 (40.8–52.4) | 48.7 (40.4–52.4) | 48.7 (39.9–51.9) | 0.092 | |||
| Carbohydrate (g/day) | 277 (220–354) | 272 (209–348) | 272 (214–339) | 272 (214–337) | 0.000 | |||
| Sucrose (g/day) | 28.0 (18.9–48.6) | 27.9 (18.9–48.9) | 27.2 (19.1–48.3) | 25.8 (18.3–48.0) | 0.051 | |||
| Glucose (g/day) | 10.6 (5.9–19.2) | 9.6 (5.7–18.1) | 9.3 (5.5–17.4) | 9.3 (5.3–17.3) | 0.064 | |||
| Fructose (g/day) | 9.3 (5.0–18.3) | 8.6 (4.7–17.2) | 8.4 (4.7–16.5) | 8.1 (4.4–16.3) | 0.066 | |||
| Lactose (g/day) | 9.4 (5.3–22.3) | 9.6 (5.1–23.1) | 9.9 (5.7–23.3) | 10.2 (5.6–25.6) | 0.004 | |||
| . | Quartiles . | . | . | . | . | |||
|---|---|---|---|---|---|---|---|---|
| . | 0.12 to <0.79 . | 0.79 to <1.15 . | 1.15 to <1.76 . | 1.76 to 14.74 . | P* . | |||
| Participants (n) | 1,425 | 1,418 | 1,421 | 1,411 | ||||
| Men (%) | 41.7 | 45.9 | 47.9 | 57.8 | 0.000 | |||
| Physically inactive (%) | 29.6 | 30.1 | 37.8 | 40.2 | 0.000 | |||
| Smokers (%) | 47.3 | 42.5 | 37.0 | 30.5 | 0.000 | |||
| Normal glucose tolerant (%)† | 91.0 | 85.8 | 80.0 | 58.8 | 0.000 | |||
| Impaired fasting glucose (%)† | 1.8 | 6.1 | 9.9 | 17.7 | 0.000 | |||
| Impaired glucose tolerant (%)† | 7.2 | 8.1 | 10.2 | 23.5 | 0.000 | |||
| Age (years) | 45.1 (40.0–50.1) | 45.0 (39.9–50.2) | 45.0 (40.0–50.2) | 45.1 (40.0–50.3) | 0.067 | |||
| BMI (kg/m2) | 23.3 (21.5–25.2) | 24.7 (22.8–26.8) | 26.1 (23.9–28.5) | 28.9 (26.0–32.2) | 0.000 | |||
| Waist (cm) | 78.0 (71.0–86.0) | 83.0 (75.0–91.0) | 87.0 (78.0–95.0) | 95.0 (87.0–104.0) | 0.000 | |||
| Energy (kcal) | 2,320 (1,965–3,042) | 2,270 (1,873–2,983) | 2,286 (1,925–3,037) | 2,282 (1,918–2,976) | 0.000 | |||
| Fat (E%) | 32.0 (27.5–39.0) | 32.7 (28.3–39.7) | 32.8 (28.0–40.2) | 32.3 (28.2–40.2) | 0.185 | |||
| Protein (E%) | 13.3 (12.7–16.3) | 13.6 (12.8–16.4) | 13.7 (12.8–16.4) | 13.8 (12.9–16.7) | 0.000 | |||
| Alcohol (E%) | 3.2 (1.1–6.5) | 2.9 (1.0–5.5) | 2.7 (0.9–5.4) | 2.7 (0.8–5.7) | 0.000 | |||
| Carbohydrate (E%) | 49.2 (40.7–53.1) | 48.8 (40.8–52.4) | 48.7 (40.4–52.4) | 48.7 (39.9–51.9) | 0.092 | |||
| Carbohydrate (g/day) | 277 (220–354) | 272 (209–348) | 272 (214–339) | 272 (214–337) | 0.000 | |||
| Sucrose (g/day) | 28.0 (18.9–48.6) | 27.9 (18.9–48.9) | 27.2 (19.1–48.3) | 25.8 (18.3–48.0) | 0.051 | |||
| Glucose (g/day) | 10.6 (5.9–19.2) | 9.6 (5.7–18.1) | 9.3 (5.5–17.4) | 9.3 (5.3–17.3) | 0.064 | |||
| Fructose (g/day) | 9.3 (5.0–18.3) | 8.6 (4.7–17.2) | 8.4 (4.7–16.5) | 8.1 (4.4–16.3) | 0.066 | |||
| Lactose (g/day) | 9.4 (5.3–22.3) | 9.6 (5.1–23.1) | 9.9 (5.7–23.3) | 10.2 (5.6–25.6) | 0.004 | |||
Data are medians and interquartile range (25th to 75th percentile) unless otherwise indicated.
P values for trend are analyzed in regression models with HOMA-IR as the continuous explanatory variable and sex as the categorical explanatory variable.
Percentages are based on individuals where both fasting and 2-h plasma glucose values were available.
Associations between carbohydrate-related dietary factors and HOMA-IR in 5,675 nondiabetic subjects in the Inter99 cohort
| . | Dependent variable . | . | . | . | |||
|---|---|---|---|---|---|---|---|
| . | HOMA ratio* (95% CI) . | P . | HOMA ratio† (95% CI) . | P . | |||
| Explanatory variables | |||||||
| Daily glycemic index (per 10 units) | 1.02 (0.99–1.04) | 0.172 | 1.01 (0.99–1.03) | 0.195 | |||
| Daily glycemic load (per 30 units) | 0.99 (0.99–1.00) | 0.029 | 0.99 (0.99–1.00) | 0.184 | |||
| Carbohydrate (per 3 E%) | 1.00 (0.99–1.00) | 0.338 | 1.00 (0.99–1.00) | 0.081 | |||
| Sucrose (per 1 E%) | 1.00 (0.99–1.00) | 0.217 | 1.00 (1.00–1.00) | 0.758 | |||
| Glucose (per 1 E%) | 0.99 (0.98–1.00) | 0.040 | 0.98 (0.97–0.99) | 0.002 | |||
| Fructose (per 1 E%) | 0.99 (0.98–1.00) | 0.036 | 0.99 (0.98–1.00) | 0.003 | |||
| Lactose (per 1 E%) | 1.02 (1.01–1.03) | 0.000 | 1.02 (1.01–1.03) | 0.000 | |||
| Dietary fiber (per 10 g/day) | 0.97 (0.96–0.99) | 0.000 | 0.97 (0.96–0.99) | 0.007 | |||
| Fruit and vegetables (per 100 g/day) | 0.99 (0.98–0.99) | 0.000 | 0.99 (0.98–0.99) | 0.000 | |||
| . | Dependent variable . | . | . | . | |||
|---|---|---|---|---|---|---|---|
| . | HOMA ratio* (95% CI) . | P . | HOMA ratio† (95% CI) . | P . | |||
| Explanatory variables | |||||||
| Daily glycemic index (per 10 units) | 1.02 (0.99–1.04) | 0.172 | 1.01 (0.99–1.03) | 0.195 | |||
| Daily glycemic load (per 30 units) | 0.99 (0.99–1.00) | 0.029 | 0.99 (0.99–1.00) | 0.184 | |||
| Carbohydrate (per 3 E%) | 1.00 (0.99–1.00) | 0.338 | 1.00 (0.99–1.00) | 0.081 | |||
| Sucrose (per 1 E%) | 1.00 (0.99–1.00) | 0.217 | 1.00 (1.00–1.00) | 0.758 | |||
| Glucose (per 1 E%) | 0.99 (0.98–1.00) | 0.040 | 0.98 (0.97–0.99) | 0.002 | |||
| Fructose (per 1 E%) | 0.99 (0.98–1.00) | 0.036 | 0.99 (0.98–1.00) | 0.003 | |||
| Lactose (per 1 E%) | 1.02 (1.01–1.03) | 0.000 | 1.02 (1.01–1.03) | 0.000 | |||
| Dietary fiber (per 10 g/day) | 0.97 (0.96–0.99) | 0.000 | 0.97 (0.96–0.99) | 0.007 | |||
| Fruit and vegetables (per 100 g/day) | 0.99 (0.98–0.99) | 0.000 | 0.99 (0.98–0.99) | 0.000 | |||
Univariate analyses.
Adjusted for age, sex, smoking, physical activity, total energy intake, BMI, and waist circumference. Values >1 indicate a positive association, and values <1 indicate an inverse association.
