Table 2. Sixteen-year risk of coronary heart disease (CHD) under different levels and durations of exposure to LDL-cholesterol, Framingham Offspring Study (1987–1991 to 2007).
| LDL level and duration* | 16-year risk of CHDa | Population risk ratiob | Population risk differenceb | Cumulative percentage intervened on | Average percentage intervened on |
|---|---|---|---|---|---|
| Low LDL (<130 mg/dL) for 16 yrsc | 8.2 (7.0 to 9.6) | 1 | 0 | 73 | 38 |
| Low LDL for 12 yrs followed very high LDL (>190 mg/dL) for 4 yrs | 8.8 (7.6 to 10.1) | 1.07 (0.95 to 1.25) | 0.6 (-0.4 to 1.9) | 100 | 56 |
| Moderate LDL (130 to <160 mg/dL) for 16 yrs | 8.9 (7.8 to 10.1) | 1.08 (0.95 to 1.22) | 0.7 (-0.4 to 1.7) | 98 | 64 |
| Low LDL for 8 yrs followed high LDL (160 to <190 mg/dL) for 8 yrs | 9.0 (7.7 to 10.3) | 1.09 (0.95 to 1.27) | 0.7 (-0.5 to 2.0) | 100 | 66 |
| Low LDL for 8 yrs followed by very high LDL for 8 yrs | 9.4 (7.8 to 11.4) | 1.14 (0.92 to 1.47) | 1.2 (-0.7 to 3.5) | 100 | 70 |
| High LDL for 16 yrs | 9.4 (7.8 to 11.5) | 1.14 (0.92 to 1.46) | 1.2 (-0.7 to 3.5) | 99 | 79 |
| Very high LDL for 16 yrs | 10.3 (7.6 to 13.9) | 1.25 (0.87 to 1.80) | 2.0 (-1.1 to 6.0) | 99 | 79 |
* Sorted by ascending CHD risk
a. There were 218 cases of CHD among 2,972 cohort participants after 39,884 person-years of follow-up. The observed risk was 8.5%.
b. In addition to LDL-cholesterol levels, we modeled 7 other covariates in the analysis: examination cycle, cigarette smoking (current smoker, and number of cigarettes per day if smoker), alcohol consumption (standard drinks per day), body mass index, diabetes, systolic blood pressure, and blood pressure medication. All models included lagged values of time-varying covariates plus baseline non-time-varying variables: sex, age, education level, marital status at examination cycle 4, and smoking history at examination cycle 3 of the Framingham Offspring Study.
c. Reference category