Centenarian Hotspots in Denmark

Background: The study of regions with high prevalence of centenarians is motivated by a desire to find determinants of healthy ageing. While existing research has focused on selected candidate geographical regions, we explore the existence of hotspots in the whole the Denmark, which is a small and homogeneous country. Methods: We performed a Kulldorff spatial scan across the whole of Denmark, searching for regions of birth, and regions of residence at age 71, where a significantly increased percentage of the cohort born 1906-1915 became centenarians. Next we compared mortality hazards for the identified regions to the rest of the country by sex and residence at age 71. Results: We found a birth hotspot of 222 centenarians, 1.37 times more than the expected number, centered on a group of fairly remote rural islands. Significantly lower mortality hazards from age 71 onwards were confined to those who were born within the hotspot and persisted over a period of at least 30 years. At age 71, we found two residence-based hotspots of 348 respectively 238 centenarians, equaling 1.46and 1.44 times the expected number. One is located in the high-income suburbs of the Danish capital and here the lower mortality hazard was confined to those who moved into the hotspot. In the second residence-based hotspot, both those who were born, and those who moved into the hotspot, showed significant lower mortality hazards. Conclusion: Within the whole of Denmark, we identified several centenarian hotspots that have different biological underpinnings. These outcomes point to complex gene-environmental interactions explaining a variety of longevity trajectories. . CC-BY-NC-ND 4.0 International license not peer-reviewed) is the author/funder. It is made available under a The copyright holder for this preprint (which was . http://dx.doi.org/10.1101/170654 doi: bioRxiv preprint first posted online Aug. 4, 2017;