Which statement about physiologic changes in the elderly is incorrect?

The statement regarding an increase in renal function in the elderly is incorrect because, generally, age-related physiological changes lead to a decline in renal function. As individuals age, there is a gradual decrease in glomerular filtration rate (GFR) and a reduction in renal mass, resulting in diminished kidney performance. This decline can affect the body's ability to clear drugs and waste products, making older adults more susceptible to the adverse effects of medications.

In contrast, the other statements reflect well-established physiological changes that occur in older adults. For example, an increase in the fat-to-lean body ratio is a typical change observed with aging, as muscle mass tends to decrease while fat mass may increase. Similarly, there is a known decrease in the liver's ability to metabolize drugs due to hepatic blood flow reduction and alterations in liver size and function with aging. Lastly, the loss of high-frequency hearing, known as presbycusis, is a common sensory change in the elderly, affecting their ability to perceive certain sounds.