Chronic inflammation in midlife is associated with a greater risk of frailty and overall poorer health in old age, according to a new Johns Hopkins study of nearly 6,000 Americans.
The findings, published in The Journal of Gerontology, found that each standard deviation of higher inflammation detected in midlife was linked to a 39 percent higher risk of frailty in participants over two decades later. The link was found to be stronger among whites than African-Americans.
Overall, the researchers found that the prevalence of late-life frailty among participants with low levels of inflammation in midlife was four to five percent, while the prevalence of late-life frailty among those with high midlife inflammation was nine percent — approximately double.
The researchers note that the findings do not necessarily establish a cause and effect relationship between chronic inflammation and frailty, a condition which is generally aligned with overall poorer health, weakness, and failure to thrive in older adults.
And although the findings are too preliminary to suggest biomarker screening for frailty, the researchers still encourage maintaining a healthy lifestyle and taking measures to prevent and treat chronic diseases to reduce inflammation, as this could help people avoid frailty in older adulthood.
“Our results also support the idea that disease processes leading to frailty may begin decades prior to its onset, in a similar manner to other chronic conditions such as dementia,” says lead study author Keenan Walker, Ph.D., a clinical neuropsychology postdoctoral fellow at the Johns Hopkins University School of Medicine.
“Middle adulthood may be an especially important period for poor health in older adults for multiple reasons. First, it is in middle age when the incidence of common chronic diseases, such as diabetes, begins to accelerate.”
“Second, compared to individuals who develop systemic disease and inflammation in later life, individuals who develop these conditions in midlife may have a longer exposure and therefore are more susceptible to deleterious physiological effects,” says Walker.
For the study, the researchers analyzed data from 5,760 adults in their 70s participating in the Atherosclerosis Risk in Communities study, a national, long-term investigation of nearly 16,000 adults living in four U.S. communities. The participants were followed over the course of five medical examinations, starting in 1987-1989, when they were in their 40s and 50s.
The participants underwent tests for five specific markers of inflammation in the bloodstream (white blood cell count, fibrinogen, von Willebrand factor and factor VIII) collected during their initial study visits.
Next, all participants who completed the fifth visit were deemed as either frail, pre-frail or robust depending upon how many of the following attributes they had at the time: exhaustion, slowness, low physical activity, weakness, and weight loss. Those deemed frail met three or more of these criteria, while those categorized as pre-frail met one or two of the criteria, and those categorized as robust met none of the criteria.
Statistical analysis was used to determine if markers of inflammation at midlife could predict later frailty, and whether race or sex affected this link.
Overall, seven percent of the participants were frail at the fifth visit in their 70s, and 48 percent were pre-frail at the fifth visit. Compared to the robust participants, those who were frail or pre-frail were older (four and three years older, respectively), more likely to be female and African-American, had lower levels of education, and had greater levels of cardiovascular risk factors, such as higher body mass index, blood pressure, and total cholesterol, and more chronic health conditions such as high blood pressure, diabetes and coronary heart disease.
Investigators also looked at measures of the blood marker C-reactive protein (CRP) — a protein that rises in response to inflammation from a variety of sources including infections, heart disease and cancer. Participants were categorized as having “low” or “elevated” CRP at these visits.
Even after adjusting for demographic characteristics such as age, sex and education, and for co-occurring conditions such as diabetes and high blood pressure, each standard deviation increase in visit two CRP was associated with a 32 percent higher chance of frailty features at visit five, occurring 21 years later.
“There are studies underway to see if dropping levels of inflammation, mostly in older age groups, can prevent the progression of declines in mobility and in the muscles that contribute to frailty,” says coauthor Jeremy Walston, M.D., the Raymond and Anna Lublin Professor of Geriatric Medicine at Johns Hopkins.
“Stay tuned — hopefully we’ll be able to say with more accuracy in the not-too-distant future that treating chronic inflammation will reduce your risk of muscle decline and related frailty.”
Source: Johns Hopkins Medicine