J Am Acad Orthop Surg. 2024 May 29. doi: 10.5435/JAAOS-D-23-00723. Online ahead of print.

ABSTRACT

INTRODUCTION: Hip fractures are life-changing injuries with associated one-year mortality up to 30%. Five locations in the world have been termed “blue zones,” where the longevity of the population is markedly higher than that of surrounding areas and there are 10 times more centenarians. The United States has one blue zone (Loma Linda, California), which is believed to be because of the lifestyle of the Seventh-day Adventist population living there. We hypothesized that patients from the blue zone experience low-energy, frailty-driven, osteoporotic hip fractures later in life and an increased postinjury longevity relative to non-blue zone control subjects.

METHODS: A review of patients treated for hip fracture between January 2010 and August 2020 from a single institution was conducted. Demographic data were collected, and the end point of mortality was assessed using death registry information, queried in April 2024. Groups were divided into blue zone and non-blue zone. Statistical analysis was conducted with P < 0.05 considered significant.

RESULTS: Complete data were available for 1,032 patients. The blue zone cohort sustained low-energy hip fractures 12 years later in life (83.2 versus 71.1, P < 0.01). Propensity score matching was used to account for this difference. After propensity score matching, age, body mass index, American Society of Anesthesiologists score, surgery performed, sex, mechanism, ethnicity, diabetes, chronic obstructive pulmonary disease, CHF, chronic kidney disease grade, dementia, surgical time, and drug/tobacco/marijuana use were similar between groups. Blue zone patients had lower mortality at both 1 and 2 years postoperatively (12% versus 24%, P = 0.03 and 20% versus 33%, P = 0.03, respectively), had more hypertension (76% versus 62%, P = 0.03), reported lower alcohol use (7% versus 20%, P < 0.01), and included more Seventh-day Adventists (64% versus 15%, P < 0.01).

CONCLUSION: The blue zone lifestyle affected the onset of frailty and delayed osteoporotic hip fracture by 12 years in this propensity-matched cohort study. Postoperative mortality was also markedly lower in the blue zone cohort.

PMID:38833726 | DOI:10.5435/JAAOS-D-23-00723