Using nationwide data, a team led by researchers from the Albert Einstein College of Medicine found that many young adults with abdominal obesity display an evident risk factor for chronic kidney disease (CKD), yet the vast majority don’t know they are at risk.

The study “Abdominal Obesity, Race and Chronic Kidney Disease in Young Adults: Results from NHANES 1999-2010,” was published in the journal PLOS ONE.

The obesity epidemic affects more than a third of adults in the United States, according to data from the National Health and Nutrition Examination Survey (NHANES) 2011–2012 survey cycle. Obesity is closely linked to the development of hypertension, dyslipidemia and diabetes mellitus, that together constitute the metabolic syndrome.

Emerging evidence suggests that kidney dysfunction in obesity may be independent of traditional CKD risk factors, namely hypertension and diabetes mellitus, and may be apparent long before these factors develop in patients with metabolic syndrome.

Researchers looked at whether abdominal obesity was linked with initial markers of CKD in a young healthy group and if the associations varied by race and/or ethnicity.

Using nationwide data collected between 1999 and 2010 by the National Health and Nutrition Examination Survey (NHANES), a total of 6,918 young adults between the ages of 20 to 40 were included in the analyses. The researchers determined that more than one-third of all young adults had abdominal obesity and that it was more predominant among non-Hispanic blacks (45.4 percent) than Mexican-Americans (40.6 percent) and non-Hispanic whites (37.4 percent).

The researchers also found that Mexican-American young adults with abdominal obesity had a higher risk of albuminuria (the presence of albumin in the urine) even among those who had normal glucose levels, normal blood pressure, and normal insulin sensitivity. Also, fewer than 5 percent of young adults with albuminuria of all races and ethnicities knew they had kidney disease.

“Even though chronic kidney disease typically manifests in older people, the disease can start much earlier, but often is not recognized early on,” study leader Michal L. Melamed, M.D., associate professor of medicine and of epidemiology and public health at Einstein and attending physician, nephrology, at Montefiore Health System, said in a recent news release.

“Because treatment options for CKD are limited, prevention is the best approach for those at risk. A healthier lifestyle in young adults will go a long way toward promoting kidney health later in life,” Melamed said.

Evidence from prior studies had indicated that abdominal obesity may damage kidney function even before kidney damage related to diabetes and hypertension (both linked to obesity).

“In this study we wanted to evaluate whether obesity is associated with CKD even in an otherwise healthy young adult population and to identify risk factors that may promote this association,” said first author Harini Sarathy, M.D., formerly a resident physician at Jacobi Medical Center, an Einstein clinical affiliate. “We also wanted to see whether race or ethnicity plays a role in linking abdominal obesity with CKD, as studies have suggested.”

According to these results, obesity should be considered an independent risk factor for CKD. Moreover, clinicians should assess for kidney damage when clinically examining obese young adults.

“Clearly, clinicians and public health officials need to do more to identify and treat young people at risk for early progressive kidney disease so they can adopt the behavioral changes to prevent CKD from occurring,” Melamed said.