Cardiovascular autonomic nervous system function and hip fracture risk: the Cardiovascular Health Study

Mortality Following Hip Fracture in Older Adults With and Without Coronary Heart Disease

BACKGROUND

Comorbidities like coronary heart disease are common among older people who sustain an osteoporotic hip fracture. However, their impact on short- and long-term mortality post-hip fracture is not well quantified.

METHODS

We examined 4092 and 1173 older adults without and with prevalent coronary heart disease, respectively. Post-hip fracture mortality rates were computed with Poisson models and hazard ratios with Cox regression. For perspective, we compared mortality rates among participants with prevalent coronary heart disease who had either a hip fracture or incident heart failure (but no hip fracture).

RESULTS

Among participants without prevalent coronary heart disease, the mortality rate post-hip fracture was 21.83 per 100 participant years, including 49.27 per 100 participant years in the first 6 months following hip fracture. Among participants with prevalent coronary heart disease, the corresponding mortality rates were 32.52 and 79.44 per 100 participant years, respectively. Participants with prevalent coronary heart disease and incident heart failure (but no hip fracture) had corresponding post-incident heart failure mortality rates per 100 participant years of 25.62 overall and 46.4 in the first 6 months. In all 3 groups, the hazard ratio for mortality was similarly elevated: 5- to 7-fold at 6 months and 1.7- to 2.5-fold beyond 5 years.

CONCLUSION

As a case study in the absolute effects of a comorbidity on post-hip fracture mortality, hip fracture in a person with coronary heart disease carries an exceedingly high mortality rate, even higher than that following incident heart failure in individuals with coronary heart disease.

Age-Related Factors Associated With The Risk of Hip Fracture

OBJECTIVE

Advancing age is a powerful risk factor for hip fractures. The biological mechanisms through which aging impacts the risk of hip fractures have not been well studied.

METHODS

Biological factors associated with "advancing age" that help to explain how aging is associated with the risk of hip fractures are reviewed. The findings are based on analyses of the Cardiovascular Health Study, an ongoing observational study of adults aged ≥65 years with 25 years of follow-up.

RESULTS

The following 5 age-related factors were found to be significantly associated with the risk of hip fractures: (1) microvascular disease of the kidneys (albuminuria and/or elevated urine-albumin-to-creatinine ratio) and brain (abnormal white matter disease on brain magnetic resonance imaging); (2) increased serum levels of carboxymethyl-lysine, an advanced glycation end product that reflects glycation and oxidative stress; (3) reduced parasympathetic tone, as derived from 24-hour Holter monitoring; (4) carotid artery atherosclerosis in the absence of clinical cardiovascular disease; and (5) increased transfatty acid levels in the blood. Each of these factors was associated with a 10% to 25% increased risk of fractures. These associations were independent of traditional risk factors for hip fractures.

CONCLUSION

Several factors associated with older age help to explain how "aging" may be associated with the risk of hip fractures. These same factors may also explain the high risk of mortality following hip fractures.

Resting heart rate, self-reported physical activity in middle age, and long-term risk of hip fracture. A NOREPOS cohort study of 367,386 men and women

Enhanced knowledge regarding modifiable risk factors for hip fractures are warranted. We aimed to study the associations between two indicators of physical fitness (resting heart rate and level of physical activity) in middle-aged individuals, and the risk of hip fractures during the subsequent three decades. Data on objectively measured resting heart rate and self-reported leisure time physical activity from a national health survey (1985-1999) was linked to a database including all hip fractures treated in Norwegian hospitals from 1994 through 2018. We calculated hazard ratios (HR) with 95 % confidence intervals (95 % CI) for hip fractures according to categories of resting heart rate (mean of two repeated measures), and leisure time physical activity level in adjusted Cox proportional hazard models. In total, 367,386 persons (52 % women) aged 40 to 45 years were included, of whom 5482 persons sustained a hip fracture during a mean follow-up of 24.8 years. Higher resting heart rate was associated with higher hip fracture risk. Men with a resting heart rate above 80 bpm, who also reported low levels of physical activity, had a HR of 1.82 (95 % CI 1.49-2.22) for hip fracture compared to men with a resting heart rate below 70 bpm who reported high levels of physical activity. The same measure of association for women was 1.62 (95 % CI 1.28-2.06). Physical fitness measured by low resting heart rate in middle age, and a high physical activity level were associated with a lower long-term risk of hip fractures in both men and women.

Research for correlation between heart rate variability parameters and bone mineral density in patients of type 2 diabetes mellitus

PURPOSE

The relationship of CAN and BMD, fracture risk is still unclear in T2DM. The aim of the present study is to investigate the correlation between heart rate variability (HRV) and BMD in T2DM.

METHODS

The study included 276 patients with T2DM aged ≥ 50 years, and Cardiovascular Autonomic Reflex Tests (CARTs) were applied to divide patients into two groups: CAN ( ±). 24 h Ambulatory ECG was assessed for HRV, BMD was measured by dual-energy X-ray bone densitometry, and FRAX scores were calculated for 10-year hip fracture risk (HF¹) and major osteoporotic fracture risk (MOF). Adjusted regression analysis was performed to investigate influence factors for BMD and fracture risk. ROC curve was used to analyze the optimal cut-off point of LF/HF for screening osteoporosis.

RESULTS

Baseline data showed significant differences in the duration of T2DM, insulin resistance index (HOMA-IR), 25-hydroxyvitamin D[25(OH)D], femoral neck BMD, hip BMD, lumbar BMD, HF¹, and MOF between the CAN ( +) and CAN (-) groups. The proportion of patients with osteoporosis increased as the degree of CAN lesion increased. Correlation analysis showed that LF/HF was significantly correlated with BMD, especially with hip (r = - 0.534, p < 0.001). Regression analysis showed that LF/HF was a risk factor for reduced BMD and increased fracture risk. The optimal cut-point value for LF/HF to predict osteoporosis by ROC curve analysis was 3.17.

CONCLUSIONS

CAN is associated with reduced BMD and increased fracture risk in patients with T2DM, and LF/HF may have the potential to be a predictor of diabetic osteoporosis and have some clinical value in early diagnosis of diabetic osteoporosis and non-traumatic fractures in T2DM.