There is growing evidence that patients with type 2 diabetes mellitus have increased cancer risk. We examined the association between diabetes, cancer, and cancer-related mortality and hypothesized that insulin sensitizers lower cancer-related mortality. Participants in the Diabetes Cardiovascular Risk and Evaluation: Targets and Essential Data for Commitment of Treatment study, a nationwide cross-sectional and prospective epidemiological study, were recruited from German primary care practices. In the cross-sectional study, subjects with type 2 diabetes mellitus had a higher prevalence of malignancies (66/1308, 5.1%) compared to nondiabetic subjects (185/6211, 3.0%) (odds ratio, 1.64; 95% confidence interval, 1.12-2.41) before and after adjustment for age, sex, hemoglobin A1c, smoking status, and body mass index. Patients on metformin had a lower prevalence of malignancies, comparable with that among nondiabetic patients, whereas those on any other oral combination treatment had a 2-fold higher risk for malignancies even after adjusting for possible confounders; inclusion of metformin in these regimens decreased the prevalence of malignancies. In the prospective analyses, diabetic patients in general and diabetic patients treated with insulin (either as monotherapy or in combination with other treatments) had a 2- and 4-fold, respectively, higher mortality rate than nondiabetic patients, even after adjustment for potential confounders (incidence of cancer deaths in patients with type 2 diabetes mellitus [2.6%] vs the incidence of cancer deaths in patients without type 2 diabetes mellitus [1.2%]). Our results suggest that diabetes and medications for diabetes, with the exception of the insulin sensitizer metformin, increase cancer risk and mortality.

Es gibt widersprüchliche Befunde darüber, ob depressive Symptome Risikofaktoren für die Neumanifestation eines Diabetes sind oder ob umgekehrt auch Diabetes ein Risikofaktor für depressive Zustände ist. Daher untersuchen wir die längsschnittlichen wechselseitigen Assoziationen zwischen depressiven Symptomen und Typ-2-Diabetes (T2D) sowie die Auswirkungen des gemeinsamen Auftretens beider Erkrankungen auf die Mortalität anhand einer Stichprobe von Hausarztpatienten im Verlauf eines im Mittel 3,5-jährigen Beobachtungszeitraums. Die depressive Symptomatik wurde anhand des Depression Screening Questionnaire (DSQ) kategorial sowie dimensional betrachtet. Die Einteilung in Patienten mit normalem Nüchternblutzucker (NBZ), erhöhtem NBZ sowie T2D (unbehandelt, medikamentös, mit Insulin/kombiniert behandelt) erfolgte nach Arztangaben beziehungsweise nach Laborbefunden zur Baseline-Untersuchung. Die Inzidenz des T2D bei Patienten mit beziehungsweise ohne depressive Symptome betrug 25,6 und 20,9 pro 1000 Personenjahre. Bei dimensionaler Betrachtung des DSQ erhöhte sich das T2D-Risiko (unadjustiert) um das 1,03-Fache [KI (95%): 1,01–1,06] bei punktweisem Anstieg des DSQ. Die Inzidenz depressiver Symptome per 1000 Personenjahre betrug 30,5 für Patienten mit normalem, 34,2 für Patienten mit erhöhtem NBZ, 36,4 für unbehandelte, 32,3 für oral behandelte und 47,8 für insulinbehandelte T2D-Patienten. Verglichen mit Patienten mit einem normalen NBZ hatten insulinbehandelte Patienten ein höheres Risiko für depressive Symptome [HR: 1,71; KI (95%): 1,03–2,83] und oral behandelte T2D-Patienten ein niedrigeres Risiko [HR: 0,58; KI (95%): 0,36–0,96]. Verglichen mit Patienten ohne T2D und depressiver Symptomatik ist das Vorliegen beider Erkrankungen mit einer erhöhten Mortalität assoziiert [HR: 2,49; KI (95%):1,45–4,28]. Die Ergebnisse deuten an, dass vor allem eine Insulinbehandlung bei T2D-Patienten mit inzidenten depressiven Symptomen assoziiert ist. / It is unclear whether depressive symptoms are a risk factor for incident diabetes or diabetes is a risk factor for depressive conditions. Therefore, we examined the longitudinal bidirectional associations between depressive symptoms and type 2 diabetes (T2D) as well as the impact of both diseases on (all cause) mortality in a sample of primary care patients over a 3.5-years follow-up period on average. Depressive symptomatology, defined by the Depression Screening Questionnaire (DSQ), was examined both categorically and dimensionally. Patients were categorized as normal fasting glucose (NFG), impaired fasting glucose (IFG), and T2D (untreated, oral antidiabetics, insulin/combined treatment) according to physician ratings and baseline lab values. Incidence rates of T2D were 25.6 and 20.9 per 1000 person–years for those with and without depressive symptoms, respectively. The unadjusted risk of incident type 2 diabetes was 1.03 times higher (CI(95%): 1.01–1.06) for each 1-point increment in DSQ score. The incidence rates of elevated depressive symptoms per 1000 person–years were 30.5 for NFG, 34.2 for IFG, 36.4 for untreated T2D, 32.3 for oral treated T2D, and 47.8 for insulin/combined-treated T2D patients. Compared to NFG patients, insulin-treated patients had a higher risk of incident depressive symptoms (HR: 1.71; CI(95%): 1.03–2.83) and oral-treated patients had a lower risk (HR: 0.58; CI(95%): 0.36–0.96). Higher mortality rates were associated with both diseases compared to patients without T2D or depressive symptoms at baseline (HR: 2.49; CI(95%):1.45–4.28). Results indicate that especially insulin treatment in T2D patients is associated with incident depressive symptoms.