Cohort Profile: The EPIC-NL study

The sine qua non of discovering novel biomarkers for early detection of ovarian cancer: carefully selected preclinical samples

This perspective discusses reports by Cramer and colleagues (beginning on page 365 in this issue of the journal) and Zhu and colleagues (beginning on page 375), which provide the first systematic and reliable comparison of a large number of candidate biomarkers for the early detection of ovarian cancer in a sample set well-suited for this purpose. This research has important implications for the future design of cancer biomarker studies.

External validation of the UK Prospective Diabetes Study (UKPDS) risk engine in patients with type 2 diabetes

AIMS/HYPOTHESIS

Treatment guidelines recommend the UK Prospective Diabetes Study (UKPDS) risk engine for predicting cardiovascular risk in patients with type 2 diabetes, although validation studies showed moderate performance. The methods used in these validation studies were diverse, however, and sometimes insufficient. Hence, we assessed the discrimination and calibration of the UKPDS risk engine to predict 4, 5, 6 and 8 year cardiovascular risk in patients with type 2 diabetes.

METHODS

The cohort included 1,622 patients with type 2 diabetes. During a mean follow-up of 8 years, patients were followed for incidence of CHD and cardiovascular disease (CVD). Discrimination and calibration were assessed for 4, 5, 6 and 8 year risk. Discrimination was examined using the c-statistic and calibration by visually inspecting calibration plots and calculating the Hosmer-Lemeshow χ(2) statistic.

RESULTS

The UKPDS risk engine showed moderate to poor discrimination for both CHD and CVD (c-statistic of 0.66 for both 5 year CHD and CVD risks), and an overestimation of the risk (224% and 112%). The calibration of the UKPDS risk engine was slightly better for patients with type 2 diabetes who had been diagnosed with diabetes more than 10 years ago compared with patients diagnosed more recently, particularly for 4 and 5 year predicted CVD and CHD risks. Discrimination for these periods was still moderate to poor.

CONCLUSIONS/INTERPRETATION

We observed that the UKPDS risk engine overestimates CHD and CVD risk. The discriminative ability of this model is moderate, irrespective of various subgroup analyses. To enhance the prediction of CVD in patients with type 2 diabetes, this model should be updated.

Non-fasting lipids and risk of cardiovascular disease in patients with diabetes mellitus

AIMS/HYPOTHESIS

The aim of this study was to examine the effect of postprandial time on the associations and predictive value of non-fasting lipid levels and cardiovascular disease risk in participants with diabetes.

METHODS

This study was conducted among 1,337 participants with diabetes from the Dutch and German (Potsdam) contributions to the European Prospective Investigation into Cancer and Nutrition. At baseline, total cholesterol, LDL- and HDL-cholesterol and triacylglycerol concentrations were measured and the ratio of total cholesterol/HDL-cholesterol was calculated. Participants were followed for incidence of cardiovascular disease.

RESULTS

Lipid concentrations changed minimally with increasing postprandial time, except for triacylglycerol which was elevated just after a meal and declined over time (1.86 at 0.1 h to 1.33 at >6 h, p for trend <0.001). During a mean follow-up of 8 years, 116 cardiovascular events were documented. After adjustment for potential confounders, triacylglycerol (HR for third tertile compared with first tertile (HR(t)₃(to)₁), 1.73 [95% CI 1.04, 2.87]), HDL-cholesterol (HR(t)₃(to)₁, 0.41 [95% CI 0.23, 0.72]) and total cholesterol/HDL-cholesterol ratio (HR(t)₃(to)₁, 1.65 [95% CI 0.95, 2.85]) were associated with cardiovascular disease, independent of postprandial time. Cardiovascular disease risk prediction using the UK Prospective Diabetes Study risk engine was not affected by postprandial time.

CONCLUSIONS/INTERPRETATION

Postprandial time did not affect associations between lipid concentrations and cardiovascular disease risk in patients with diabetes, nor did it influence prediction of cardiovascular disease. Therefore, it may not be necessary to use fasting blood samples to determine lipid concentrations for cardiovascular disease risk prediction in patients with diabetes.

Tea and coffee consumption and cardiovascular morbidity and mortality

OBJECTIVE

To examine the associations of coffee and tea consumption with risk of morbidity and mortality of stroke and coronary heart disease (CHD) and with all-cause mortality.

METHODS AND RESULTS

Coffee and tea consumption were assessed with a validated food-frequency questionnaire, and 37 514 participants were observed for 13 years for the occurrence of cardiovascular morbidity and mortality. A U-shaped association between coffee and CHD was found, with the lowest hazard ratio (HR [95% CI]) for 2.1 to 3.0 cups per day (0.79 [0.65 to 0.96]; P(trend)=0.01). Tea was inversely associated with CHD, with the lowest HR (95% CI) for more than 6.0 cups per day (0.64 [0.46 to 0.90]; P(trend)=0.02). No associations between tea or coffee and stroke were found (P(trend)=0.63 and P(trend)=0.32, respectively). Although not significant, coffee slightly reduced the risk for CHD mortality (HR, 0.64; 95% CI, 0.37 to 1.11; P(trend)=0.12) for 3.1 to 6.0 cups per day. A U-shaped association between tea and CHD mortality was observed, with an HR of 0.55 (95% CI, 0.31 to 0.97; P(trend)=0.03) for 3.1 to 6.0 cups per day. Neither coffee nor tea was associated with stroke (P(trend)=0.22 and P(trend)=0.74, respectively) and all-cause mortality (P(trend)=0.33 and P(trend)=0.43, respectively).

CONCLUSIONS

High tea consumption is associated with a reduced risk of CHD mortality. Our results suggest a slight risk reduction for CHD mortality with moderate coffee consumption and strengthen the evidence on the lower risk of CHD with coffee and tea consumption.

Coffee and tea consumption and risk of type 2 diabetes

AIMS/HYPOTHESIS

The aim of this study was to examine the association of consumption of coffee and tea, separately and in total, with risk of type 2 diabetes and which factors mediate these relations.

METHODS

This research was conducted as part of the Dutch Contribution to the European Prospective Investigation into Cancer and Nutrition, which involves a prospective cohort of 40,011 participants with a mean follow-up of 10 years. A validated food-frequency questionnaire was used to assess coffee and tea consumption and other lifestyle and dietary factors. The main outcome was verified incidence of type 2 diabetes. Blood pressure, caffeine, magnesium and potassium were examined as possible mediating factors.

RESULTS

During follow-up, 918 incident cases of type 2 diabetes were documented. After adjustment for potential confounders, coffee and tea consumption were both inversely associated with type 2 diabetes, with hazard ratios of 0.77 (95% CI 0.63-0.95) for 4.1-6.0 cups of coffee per day (p for trend = 0.033) and 0.63 (95% CI: 0.47-0.86) for >5.0 cups of tea per day (p for trend = 0.002). Total daily consumption of at least three cups of coffee and/or tea reduced the risk of type 2 diabetes by approximately 42%. Adjusting for blood pressure, magnesium, potassium and caffeine did not attenuate the associations.

CONCLUSIONS/INTERPRETATION

Drinking coffee or tea is associated with a lowered risk of type 2 diabetes, which cannot be explained by magnesium, potassium, caffeine or blood pressure effects. Total consumption of at least three cups of coffee or tea per day may lower the risk of type 2 diabetes.