Normative data on cardiovascular autonomic function in Greenlandic Inuit

Abstract

IntroductionDiabetes is increasing among Greenlandic Inuit; however, the prevalence of cardiovascular autonomic neuropathy (CAN) is yet unknown. The assessment of CAN requires an ability to differentiate between normal and abnormal. The aim was to establish normative reference data of cardiovascular autonomic function in Greenlandic Inuit.Research design and methodsIn this cross-sectional study, cardiovascular autonomic function was evaluated in participants without diabetes during the Greenlandic Population Study 2018 and in the town Qasigiannguit in 2020. Assessment included cardiovascular autonomic reflex tests (CARTs) and power spectral analysis of heart rate variability (HRV). Normative reference limits were estimated by applying piecewise linear quantile regression models at the fifth percentile. Models were adjusted for age and sex.ResultsBased on examinations of 472 participants (61.7% females), normative reference data was established for all outcomes. Mean age was 54 years (SD 13.1). Higher age was inversely associated with all outcomes of CARTs and HRV. A linear fall in cardiovascular autonomic function tended to level off beyond age of 60 or 70 years for supine-to-upright position ratio and low frequency power. However, the number of observations in subjects older than 60 or 70 years was limited, which may have caused a flattening of the curve around that age. No other associations were found.ConclusionsThe general level of the CARTs and HRV for all age groups is notably lower than in previous studies from other nationalities. We speculate that sociodemographic and cultural aspects of the Greenlandic Inuit population including body mass index, smoking, physical activity and alcohol consumption may have affected the cardiovascular autonomic function.

Normative Data on Measures of Cardiovascular Autonomic Neuropathy and the Effect of Pretest Conditions in a Large Danish Non-Diabetic CVD-Free Population

“…However, the described plateau phase for some CAN outcomes has only been demonstrated in a few studies (22,37). Previously, we have published normative data on CARTs and HRV indices in a Greenlandic Inuit population (22). Here, the outcomes of the lying-to-standing test plateaued at the age of 60 years.…”

“…It is well-established that age-dependent decreases in both CARTs and HRV are present in healthy individuals (19,20,(22)(23)(24). However, the described plateau phase for some CAN outcomes has only been demonstrated in a few studies (22,37).…”

“…Few efforts have been made to define normal ranges of HRV indices. However, these have been performed either on relatively small cohorts (19,22) by the use of very short-term measures (<5 minutes) (23), on long-term Holter-monitor data (24) or in cohorts with relatively narrow age intervals (25). These approaches cannot be translated into applicable standards for shortterm HRV assessment.…”

The Greenland population health survey 2018 – methods of a prospective study of risk factors for lifestyle related diseases and social determinants of health amongst Inuit

“…The potential of the study is to contribute to the continued monitoring of risk factors and health conditions that are part of Inuuneritta and to study the epidemiology of cardiometabolic diseases and other chronic diseases as well as behavioural risk factors among the Inuit. Some results of the 2018 survey for diet [ 45–49 ], diabetes complications [ 50 , 51 ], alcohol [ 52 ], muscle strength [ 53 ], wellbeing of older adults [ 34 , 54 ,] and mental health among youth [ 54 , 55 ,] have been published. The population health surveys will be continued and enhanced with support from the Greenland Government.…”