Age Dynamics of Physiological Indices as Determinants of Healthy Life: Evidence from Longitudinal Data
Konstantin G. Arbeev, Duke University
Svetlana V. Ukraintseva, Duke University
Alexander Kulminski, Duke University
Liubov Arbeeva, Duke University
Lucy Akushevich, Duke University
Irina V. Culminskaya, Duke University
Longitudinal data provide possibilities to analyze how dynamics of physiological indices impact morbidity/mortality risks. We analyzed the relationship between “healthy lifespan” (defined as free of cancer, cardiovascular and diabetes lifespan) and longitudinal observations of six physiological indices: body mass index, diastolic blood pressure, hematocrit, pulse pressure, pulse rate, and serum cholesterol, in the Framingham Heart Study using the stochastic process model of aging. We evaluated that: 1) “optimal” trajectories of the physiological indices (minimizing the risk of “unhealthy life”) are age-dependent; 2) these trajectories deviate from those resulting from the processes of allostatic adaptation of an organism; 3) ranges of “tolerable” deviations of indices from the “norm” reduce with age, i.e., U-shapes of the risk narrow with age. The model estimates that individuals might enjoy up to several additional years of healthy life if their indices followed the “optimal” age trajectories. The mechanisms contributing to observed results are discussed.