In otherwise healthy individuals, obesity was linked to 6.7 more
cases of kidney disease for every 1,000 people over five years than
occurred among normal-weight patients. Being overweight was
associated with 3.5 more cases per 1,000.
The findings contradict some previous research that has found people
with what’s known as “metabolically healthy obesity” may not face an
increased risk of kidney problems, cardiovascular disease or other
issues linked to excess weight, said lead study author Dr. Yoosoo
Chang of Kangbuk Samsung Hospital Total Healthcare Center in Seoul.
“Obese individuals who are considered 'healthy' because they don’t
currently have heart disease or metabolic risk factors should not be
assumed healthy,” Chang said by email.
“The presence of obesity appears to be enough to increase a person’s
risk of future chronic kidney disease as well as other
obesity-associated diseases including heart disease,” Chang added.
“It’s important that people maintain a healthy weight and lifestyle
to prevent future obesity-related complications.”
Globally, 1.9 billion adults are overweight or obese, according to
the World Health Organization. Obesity increases the risk of heart
disease, diabetes, kidney complications, joint disorders and certain
Risk factors for kidney disease include hypertension, diabetes,
obesity, smoking, elevated cholesterol and high blood sugar as well
as family history and advanced age.
To assess how weight might influence the odds that patients develop
chronic kidney disease, Chang and colleagues analyzed data on more
than 62,000 young and middle-aged people.
About 59 percent of the participants were normal weight at the start
of the study, while 21 percent were overweight, 13 percent were
obese and 7 percent weighed too little.
People were about 36 years old at the start of the study, and they
were followed for an average of six years.
The link between obesity and kidney disease was more pronounced
among older people in the study.
Among those under age 40, obesity was associated with 3.5 more cases
of kidney disease for every 1,000 people than occurred with
normal-weight patients over five years. But after 40, the increased
risk connected to obesity jumped to 19 cases per 1,000 people.
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One limitation of the study is that researchers identified obese
people using data on body mass index (BMI), a ratio of weight
relative to height that doesn’t distinguish between fat and muscle,
the authors note. They also lacked data on how long people were
obese or how weight changed over time.
Even so, the findings suggest that doctors should warn obese
patients about the risk of kidney disease and encourage them to make
lifestyle changes to shed excess pounds, the authors conclude in
Annals of Internal Medicine.
Because some previous studies have tied obesity to better survival
among patients with advanced kidney disease and fewer deaths from
cancer and cardiovascular disease, however, more research is still
needed to pinpoint the exact nature of the relationship between
weight and kidney problems, noted Dr. Georges Nakhoul of the
Cleveland Clinic Glickman Urological and Kidney Institute in Ohio.
“The idea of 'healthy obesity' came from the observation that
patients with chronic diseases such as end stage renal disease
appear to have an improved survival when their BMI is elevated,”
Nakhoul, who wasn’t involved in the study, said by email.
“Obesity being a known cardiovascular risk factor, this finding was
somewhat counter-intuitive and hence has been named 'the obesity
paradox,'” he said.
SOURCE: http://bit.ly/1i46lF7 Annals of Internal Medicine, online
February 8, 2016.
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