Increased levels of triglycerides, BMI and blood pressure and low physical activity increase the risk of diabetes in Swedish women. A prospective 18-year follow-up of the BEDA study.

AIM: To investigate risk factors for the development of diabetes in middle-aged women.
METHODS: A random population sample of 1351 women without prior diabetes or cardiovascular disease, aged 39-65 years, took part in a screening study in 1979-1981 with questionnaires, physical examination and blood sampling. Development of diabetes up to 1998 was identified at a second examination in 1997-1998.
RESULTS: Seventy-three women (5.4%) were diagnosed with diabetes during follow-up. As expected, obesity resulted in a rising age-adjusted risk with hazards ratio 3.2 [95% confidence interval (CI) 1.3, 8.1] at body mass index (BMI) 24-27 kg/m(2), and 8.3 (3.5, 19.7), at BMI > or = 27, compared with BMI < 22 kg/m(2). S-triglycerides (TG) carried a steeply increasing age-adjusted risk with hazards ratio 4.0 (95% CI 2.1, 7.6) already at s-TG 1.0-1.4 mmol/l, 7.1 (3.6, 14.0) at s-TG 1.5-1.9 mmol/l and 9.3 (4.3, 20.2) at s-TG > or = 2.0 mmol/l compared with s-TG < 1.0 mmol/l. Increasing systolic blood pressure (SBP) to 130-144, 145-159 and > or = 160 mmHg escalated the hazards ratio of diabetes to 1.6 (0.8, 3.3), 3.6 (1.7, 7.4) and 5.6 (2.7, 11.4), respectively, compared with SBP < 130 mmHg. Also, low physical activity predicted diabetes, with hazards ratio 2.1 (1.3, 3.3) for sedentary compared with non-sedentary activity. Smoking was not associated with increased risk of diabetes. After adjustment for BMI, SBP and physical activity, increasing TG level remained a strong and significant risk factor for diabetes [hazards ratio 3.0 (1.6, 5.7), 3.7 (1.8, 7.7) and 4.5 (2.0, 10.0), P < 0.001].
CONCLUSIONS: Among middle-aged Swedish women even very slightly elevated s-TG resulted in a considerably enhanced risk of developing diabetes, which was independent of age, BMI, blood pressure and physical activity.