Table 2.
Adjusted logistic regression models for periodontitis and vitamin D exposures associated with HOMA-IR, pre-diabetes, and type 2 diabetes among adults over 30 years of age from the 2009–2010 NHANES
| Outcomes | Exposures | Point estimate (95% CI) | ||
| Unadjusted models | Minimally adjusted models* | Fully adjusted models† | ||
| HOMA-IR‡ | Periodontitis§ | 1.31 (0.85 to 1.50) | 1.00 (0.67 to 1.49) | 1.09 (0.70 to 1.71) |
| Vitamin D3 insufficiency¶ | 2.03 (1.62 to 2.53) | 1.86 (1.44 to 2.39)** | 1.40 (1.06 to 1.84)** | |
| Vitamin D insufficiency | 2.02 (1.51 to 2.69) | 1.80 (1.29 to 2.51)** | 1.34 (0.95 to 1.89) | |
| Pre-diabetes†† | Periodontitis§ | 1.98 (1.5 to 2.62) | 1.18 (0.85 to 1.63) | 1.13 (0.80 to 1.61) |
| Vitamin D3 insufficiency¶ | 1.17 (0.88 to 1.54) | 1.04 (0.74 to 1.47) | 0.89 (0.64 to 1.23) | |
| Vitamin D insufficiency | 1.42 (1.08 to 1.86) | 1.24 (0.84 to 1.83) | 1.06 (0.72 to 1.55) | |
| Type 2 diabetes‡‡ | Periodontitis§ | 2.74 (1.65 to 4.54)** | 1.51 (0.89 to 2.55) | 1.65 (1.02 to 2.70)** |
| Vitamin D3 insufficiency¶ | 1.82 (1.09 to 3.05)** | 1.84 (1.07 to 3.15)** | 1.60 (0.97 to 2.63) | |
| Vitamin D insufficiency | 1.33 (0.85 to 2.09) | 1.24 (0.74 to 2.07) | 1.12 (0.70 to 1.80) | |
*Minimally adjusted model, age, sex, race/ethnicity, poverty income ratio, season, smoking, and physical activity.
†Fully adjusted model, age, sex, race/ethnicity, education, insurance, season, smoking, physical activity, and body mass index.
‡HOMA-IR ≥4.17 (population-specific 75th percentile) established using fasting glucose and insulin levels by the following formula: HOMA-IR=[glucose (mmol/L)×insulin (μU/mL) / 22.5]. HOMA-IR excluded those with diagnosed and undiagnosed type 2 diabetes.
§Case definitions for periodontitis based on the definition from the Division of Oral Health at the Centers for Disease Control and Prevention, in collaboration with the American Academy of Periodontology.
¶Serum vitamin D (25(OH)D) and vitamin D3 (25(OH)D3) insufficiency is defined as levels <50 nmol/L or <20 ng/mL.
**Significance at p<0.05. Statistically significant values are shown in bold.
††Pre-diabetes based on the level of hemoglobin A1c of 5.7%–6.4% (39–47 mmol/mol), fasting plasma glucose level of 100–125 mg/dL, or adults who reported having been told by a health professional that they have any of the following: pre-diabetes, impaired fasting glucose, impaired glucose tolerance, or borderline diabetes. Pre-diabetes excluded those with diagnosed and undiagnosed type 2 diabetes.
‡‡Type 2 diabetes based on self-report of a previous diagnosis by a physician or other health professionals, or based on the level of hemoglobin A1c of 6.5% or greater and fasting plasma glucose level of 126 mg/dL or greater.
25(OH)D, 25-hydroxyvitamin D; 25(OH)D3, 25-hydroxyvitamin D3; HOMA-IR, homeostatic model assessment for insulin resistance; NHANES, National Health and Nutrition Examination Survey.