Diabetic Retinopathy Predicts Risk of Alzheimer's Disease: A Danish Registry-Based Nationwide Cohort Study.

BACKGROUND: Retinal neurodegeneration is evident in early diabetic retinopathy (DR) which may be associated with other neurodegenerative diseases like Alzheimer's disease (AD). OBJECTIVE: To investigate diabetes and DR as a risk marker of present and incident AD. METHODS: A register-based cohort study was performed. We included 134,327 persons with diabetes above 60 years of age, who had attended DR screening, and 651,936 age- and gender-matched persons without diabetes. RESULTS: At baseline, the prevalence of AD was 0.7% and 1.3% among patients with and without diabetes, respectively. In a multivariable regression model, patients with diabetes were less likely to have AD at baseline (adjusted OR 0.63, 95% CI 0.59-0.68). During follow-up, incident AD was registered for 1473 (0.35%) and 6,899 (0.34%) persons with and without diabetes, respectively. Compared to persons without diabetes, persons with diabetes and no DR had a lower risk to develop AD (adjusted HR 0.87, 95% CI 0.81-0.93), while persons with diabetes and DR had higher risk of AD (adjusted HR 1.24, 95% CI 1.08-1.43). When persons with diabetes and no DR were used as references, a higher risk of incident AD was observed in persons with DR (adjusted HR 1.34, 95% CI 1.18-1.53). CONCLUSION: Individuals with diabetes without DR were less likely to develop AD compared to persons without diabetes. However, individuals with DR had a 34% higher risk of incident AD, which raise the question whether screening for cognitive impairment should be done among individuals with DR.

Interactions between ocular and systemic disease using national register-based data in the Danish Excellence Centre in Ophthalmic Epidemiology (DECODE-EYE): study perspective.

PURPOSE: The Danish Excellence Centre in Ophthalmic Epidemiology (DECODE-EYE) is a national research collaboration formed in order to study the real-life interaction between ocular and systemic disease based on the entire Danish population. Here, we aim to describe the study design and the methodology, which will be used. METHODS: We will extract data from various healthcare registers and databases including the Danish Civil Registration System (unique personal identifier), the Danish National Patient Register (inpatient and outpatient visits), the Danish National Prescription Registry (redeemed prescription drugs), the National Health Service Register (data on health services in primary health care), the Danish Register of Cause of Death (data on cause of death), Statistics Denmark (demographic and socioeconomic data), the Danish Registry of Diabetic Retinopathy (level of diabetic retinopathy (DR) in diabetes patients) and the database of the Danish Association of the Blind (date and cause of blindness). Relevant registers will be linked by the unique personal identifier, and associations will be examined cross-sectional and/or longitudinally, in principle in 1:5 age- and gender-matched case-control cohort studies. CONCLUSION: Denmark has a strong tradition in register-based healthcare research, given a high number of validated national registers and databases. DECODE-EYE will provide Danish, large-scale data on associations between ocular and systemic disease. With a target population of 5.8 million individuals, twelve separate studies (Protocols A-L) have initially been designed to be studied in the upcoming years. These will provide novel data on interactions between systemic disease and relevant ophthalmological end-points like blindness, DR, glaucoma, corneal disease, retinal vascular disease, cataract and intravitreal angiostatic treatment.

Morbidity and medicine prescriptions in a nationwide Danish population of patients diagnosed with polycystic ovary syndrome.

OBJECTIVE: The prevalence of type 2 diabetes is increased in polycystic ovary syndrome (PCOS), but the prevalence of other diseases is not clarified. We aimed to investigate morbidity and medicine prescriptions in PCOS. DESIGN: A National Register-based study. METHODS: Patients with PCOS (PCOS Denmark and an embedded cohort; PCOS Odense University Hospital (OUH)) and one control population. Premenopausal women with PCOS underwent clinical and biochemical examination (PCOS OUH, n=1217). PCOS Denmark (n=19 199) included women with PCOS in the Danish National Patient Register. Three age-matched controls were included per patient (n=57 483). MAIN OUTCOME MEASURES: Diagnosis codes and filled prescriptions. RESULTS: The mean (range) age of the PCOS Denmark group and controls was 30.6 (12-60) years. Patients in PCOS Denmark had higher Charlson index, higher prevalence of diabetes, dyslipidemia, and hypertension than controls. PCOS was associated with a two times increased risk of stroke and thrombosis, whereas the risk of other cardiovascular diseases was not increased. Thyroid disease, asthma, migraine, and depression were more prevalent in PCOS Denmark vs controls, whereas fractures were rarer. Infertility was increased in patients compared with controls, but the mean number of births was higher in PCOS. Medicine prescriptions within all diagnosis areas were significantly higher in PCOS patients than in controls.In PCOS OUH, polycystic ovaries (PCO) and irregular menses were associated with a more adverse metabolic risk profile, but individual Rotterdam criteria were not associated with cardiometabolic diagnoses. CONCLUSION: Cardiometabolic and psychiatric morbidity were significantly increased in a Danish population with PCOS. Medical diseases are frequent also in young patients with PCOS.