Table 1

Age-adjusted prevalence and adjusted ORs (95% CIs) of the surrogate markers of IR by quintiles of serum 25(OH)D and PTH concentrations among U.S. adults aged ≥20 years without physician-diagnosed diabetes, NHANES 2003–2006 (n = 3,206)*

nHyperinsulinemiaHigh HOMA-IRHigh GHbFasting hyperglycemia2-h hyperglycemia†
Quintiles of 25(OH)D
    Prevalence (%)
        Q1 (<15 ng/ml)69037.0 (32.3–42.0)37.6 (32.8–42.7)10.8 (8.6–13.4)32.2 (27.4–37.2)26.0 (22.9–29.3)
        Q2 (15–<21 ng/ml)73133.5 (29.2–38.1)34.2 (29.8–38.9)6.8 (5.1–8.9)32.6 (29.1–36.3)23.0 (18.8–27.8)
        Q3 (21–<25 ng/ml)55823.6 (19.9–27.9)22.7 (18.5–27.4)5.3 (3.6–7.5)31.8 (28.0–35.9)21.0 (16.8–25.9)
        Q4 (25–<31 ng/ml)62917.6 (13.2–23.1)17.7 (13.3–23.0)4.6 (3.2–6.6)31.4 (26.4–36.9)16.8 (11.7–23.5)
        Q5 (≥31 ng/ml)59813.3 (9.7–18.0)13.9 (10.4–18.5)2.8 (1.8–4.3)25.7 (21.4–30.6)13.6 (8.2–21.6)
        Ptrend<0.001<0.001<0.0010.035<0.001
    Model 1
        Q1 (<15 ng/ml)6901.001.001.001.001.00
        Q2 (15–<21 ng/ml)7310.81 (0.61–1.08)0.81 (0.62–1.07)0.56 (0.39–0.81)0.96 (0.74–1.24)0.82 (0.58–1.16)
        Q3 (21–<25 ng/ml)5580.49 (0.38–0.62)0.44 (0.33–0.60)0.42 (0.26–0.68)0.89 (0.67–1.18)0.73 (0.48–1.12)
        Q4 (25–<31 ng/ml)6290.34 (0.23–0.51)0.33 (0.23–0.47)0.36 (0.22–0.59)0.86 (0.61–1.20)0.52 (0.30–0.90)
        Q5 (≥31 ng/ml)5980.24 (0.17–0.36)0.25 (0.17–0.36)0.20 (0.12–0.33)0.64 (0.48–0.86)0.39 (0.20–0.76)
        Wald-Chisq P<0.001<0.001<0.0010.0060.002
        Ptrend<0.001<0.001<0.0010.0050.001
    Model 2
        Q1 (<15 ng/ml)6901.001.001.001.001.00
        Q2 (15–<21 ng/ml)7310.80 (0.61–1.06)0.80 (0.61–1.05)0.69 (0.45–1.07)0.94 (0.70–1.25)0.77 (0.52–1.15)
        Q3 (21–<25 ng/ml)5580.45 (0.36–0.58)0.42 (0.31–0.56)0.58 (0.35–0.96)0.88 (0.66–1.18)0.68 (0.43–1.05)
        Q4 (25–<31 ng/ml)6290.32 (0.21–0.47)0.31 (0.21–0.44)0.52 (0.29–0.93)0.84 (0.58–1.23)0.48 (0.28–0.85)
        Q5 (≥31 ng/ml)5980.22 (0.15–0.34)0.23 (0.15–0.34)0.30 (0.17–0.51)0.65 (0.46–0.92)0.36 (0.16–0.77)
        Wald-Chisq P<0.001<0.001<0.0010.0340.003
        Ptrend<0.001<0.001<0.0010.0160.002
    Model 3
        Q1 (<15 ng/ml)6901.001.001.001.001.00
        Q2 (15–<21 ng/ml)7311.04 (0.74–1.46)1.02 (0.73–1.41)0.75 (0.46–1.23)1.01 (0.77–1.32)0.79 (0.54–1.15)
        Q3 (21–<25 ng/ml)5580.63 (0.43–0.92)0.54 (0.36–0.80)0.74 (0.43–1.29)1.08 (0.82–1.42)0.75 (0.50–1.14)
        Q4 (25–<31 ng/ml)6290.44 (0.27–0.73)0.41 (0.26–0.63)0.70 (0.39–1.26)1.07 (0.78–1.47)0.58 (0.34–0.98)
        Q5 (≥31 ng/ml)5980.42 (0.24–0.71)0.41 (0.25–0.66)0.46 (0.25–0.82)0.87 (0.64–1.17)0.50 (0.23–1.01)
        Wald-Chisq P<0.001<0.0010.0980.4890.082
        Ptrend<0.001<0.0010.0190.3620.024
Quintiles of PTH
    Prevalence (%)
        Q1 (<27 pg/ml)56416.0 (12.6–20.1)15.6 (11.7–20.5)4.2 (2.3–7.6)30.3 (24.7–36.6)13.2 (8.2–20.5)
        Q2 (27–<34 pg/ml)57118.1 (14.4–22.4)20.0 (15.5–23.5)3.1 (1.9–5.1)29.2 (24.9–33.9)20.0 (16.1–24.7)
        Q3 (34–<42 pg/ml)63524.1 (21.0–27.5)23.4 (20.2–26.9)5.0 (3.7–6.8)29.4 (24.4–35.0)20.7 (15.8–26.7)
        Q4 (42–<54 pg/ml)68531.3 (27.3–35.7)31.9 (28.2–35.9)6.8 (5.1–9.1)28.9 (25.2–32.9)24.4 (19.5–30.1)
        Q5 (≥54 pg/ml)75134.4 (29.9–39.2)33.4 (28.7–38.6)8.5 (6.9–10.3)37.3 (33.1–41.7)20.7 (16.5–25.6)
        Ptrend<0.001<0.001<0.0010.036‡0.007
    Model 1
        Q1 (<27 pg/ml)5641.001.001.001.001.00
        Q2 (27–<34 pg/ml)5711.28 (0.94–1.75)1.46 (1.00–2.14)0.87 (0.37–2.06)1.07 (0.74–1.54)1.79 (0.93–3.45)
        Q3 (34–<42 pg/ml)6351.83 (1.33–2.52)1.76 (1.19–2.62)1.38 (0.66–2.86)1.06 (0.71–1.58)2.05 (1.21–3.48)
        Q4 (42–<54 pg/ml)6852.70 (1.92–3.80)2.81 (1.98–3.99)1.96 (1.03–3.70)1.05 (0.71–1.56)2.59 (1.30–5.17)
        Q5 (≥54 pg/ml)7513.16 (2.34–4.27)3.08 (2.13–4.45)2.50 (1.30–4.79)1.59 (1.08–2.34)1.98 (1.08–3.64)
        Wald-Chisq P<0.001<0.001<0.0010.0050.040
        Ptrend<0.001<0.001<0.0010.0080.052
    Model 2
        Q1 (<27 pg/ml)5641.001.001.001.001.00
        Q2 (27–<34 pg/ml)5711.26 (0.93–1.73)1.44 (0.98–2.11)0.82 (0.35–1.92)1.02 (0.72–1.46)1.71 (0.86–3.41)
        Q3 (34–<42 pg/ml)6351.72 (1.25–2.37)1.66 (1.11–2.47)1.30 (0.65–2.58)1.00 (0.67–1.49)1.89 (1.04–3.46)
        Q4 (42–<54 pg/ml)6852.52 (1.79–3.56)2.61 (1.82–3.74)1.72 (0.92–3.19)0.99 (0.66–1.47)2.38 (1.09–5.20)
        Q5 (≥54 pg/ml)7512.82 (2.04–3.90)2.72 (1.84–4.02)1.98 (1.04–3.74)1.48 (0.97–2.26)1.73 (0.86–3.47)
        Wald-Chisq P<0.001<0.001<0.0010.0240.016
        Ptrend<0.001<0.0010.0010.0310.209
    Model 3
        Q1 (<27 pg/ml)5641.001.001.001.001.00
        Q2 (27–<34 pg/ml)5711.12 (0.87–1.46)1.33 (0.92–1.94)0.75 (0.31–1.83)0.97 (0.66–1.43)1.55 (0.75–3.23)
        Q3 (34–<42 pg/ml)6350.98 (0.70–1.38)0.92 (0.60–1.41)1.01 (0.48–2.11)0.82 (0.56–1.20)1.52 (0.86–2.70)
        Q4 (42–<54 pg/ml)6851.37 (0.94–1.99)1.42 (0.98–2.05)1.19 (0.62–2.26)0.74 (0.49–1.10)1.67 (0.78–3.55)
        Q5 (≥54 pg/ml)7511.39 (0.99–1.96)1.29 (0.85–1.96)1.20 (0.61–2.37)1.13 (0.75–1.72)1.06 (0.57–1.94)
        Wald-Chisq P0.1190.0060.3270.0190.096
        Ptrend0.0490.2310.1630.4300.267
  • Data are n or ORs (95 CIs). Model 1: adjusted for age and sex; model 2: adjusted for age, sex, race/ethnicity (non-Hispanic white, non-Hispanic black, Mexican American, and other), education (< high-school diploma, high-school graduate, and > high-school diploma), smoking (current, former, and never), heavy alcohol drinking (>2 drinks/day in men and >1 drink/day in women), and physical activity (engaging in moderate or vigorous physical activity daily for at least 10 min); and model 3: adjusted for variables in model 2 plus abdominal obesity (waist circumference >102 cm for men and >88 cm for women), BMI (continuous, calculated from measured weight and height), and serum concentrations of calcium (continuous) and PTH (or vitamin D).

  • *The weighted 75th percentile cutoff points were 12.4 mU/l for fasting plasma insulin and 3.1 for HOMA-IR.

  • †Data from NHANES 2005–2006 only (n = 1,412 in total).

  • ‡For a quadratic trend. Q, quintile.