Recent discoveries about diabetes

Sept. 1, 2009

Severe childhood obesity rate triples

In the last quarter century, rates of severe childhood
obesity have tripled — putting many children at risk for diabetes and
heart disease — according to a report in Academic Pediatrics by
an obesity expert at Brenner Children's Hospital, part of Wake Forest
University Baptist Medical Center. The research was published online and
will appear in this month's print edition, and was supported, in part,
by the National Institutes of the Health and the Robert Wood Johnson

Lead author Joseph Skelton, MD, and director of the
Brenner FIT (Families in Training) Program and his colleagues compared
data from the National Health and Nutrition Examination Survey, or
NHANES. They looked at the prevalence of obesity and severe obesity in a
study population of 12,384 children, representing approximately 71
million U.S. children ages 2 to 19 years.

Severe childhood obesity is a new classification for
children and describes those with a body mass index (BMI) that is equal
to or greater than the 99th percentile for age and gender. For example,
a 10-year-old child with a BMI of 24 would be considered severely obese,
whereas in an adult, that is considered a normal BMI. An expert
committee convened by the American Medical Association, the Centers for
Disease Control and the Department of Health and Human Services proposed
the new classification in 2007.

Skelton and colleagues' research is the first of its
kind to use the new classification and detail the severity of the
problem. They found that the prevalence of severe obesity tripled (from
0.8% to 3.8%) in the period from 1976 to 1980, to 1999 to 2004. Based on
the data, there are 2.7 million children in the United States who are
considered severely obese. Increases in severe obesity were highest
among African-Americans, Mexican-Americans, and among those below the
poverty level.

Researchers also looked at the impact of severe
obesity and found that a third of children in the severely obese
category were classified as having metabolic syndrome, a group of risk
factors for heart attack, stroke, and diabetes. These risk factors
include higher-than-normal blood pressure, cholesterol, and insulin

'Brown fat' as weapon in obesity war
“Brown” fat (brown adipose tissue) is the newest weapon in the battle against obesity. A good type of fat — tagged “brown fat''— converts stored energy into heat. It was long known to exist in infants between their shoulder blades but had been thought to disappear with age. Three research groups reported earlier this year that brown fat exists in some adults, and two other research groups reported finding cellular switches that can be flipped on to make brown fat cells out of ordinary skin cells and other types of cells.

The discoveries raise the possibility that in the
future, obesity could be treated by spurring the growth of brown fat
cells in patients, transplanting such cells, or increasing the activity
level of patients' existing brown fat.

This year, the varied interests of these five groups
in “brown” fat converge. One branch of long-term research attempted to
determine how such cells formed in the body. The other branch found
radiologists used a particular type of imaging to search for tumors,
imaging that measures glucose uptake. The imaging results found active
areas in patients that were not tumors. The scientists thought those
could be “brown” fat.

Bruce Spiegelman, PhD, professor of cell biology at
the Dana-Farber Cancer Institute (a principal teaching affiliate at
Harvard Medical School), has spent years investigating “brown” fat
formation. His research was supported by grants from the National
Institutes of Health and the Picower Foundation. He reported in the
journal Nature in July that last year, his research team found
two proteins that turn skin cells into “brown” fat. The group took skin
cells from mice, inserted genes that flipped the molecular switches to
force the cells to turn into “brown” fat, then transplanted the tissue
into mice. Imaging showed that the tissue was active, like normal
“brown” fat.

Spiegelman said future research will examine whether
increasing brown fat affects a mouse's weight, and whether it might be
possible to do something analogous in people.

Work by all of the researchers is likely to motivate pharmaceutical
companies to figure out how to stimulate “brown” fat, either with a drug
that can promote its growth or activity, or by turning cells into “brown”
fat and transplanting it into people.

Environment suspect found in diabetes, Alzheimer's, and Parkinson's

n a new study published in the July issue of the
Journal of
Alzheimer's Disease — researchers at Rhode Island
Hospital reveal a substantial link between increased levels of nitrates
in the environment and in food, with increased deaths from diseases,
including Alzheimer's, diabetes mellitus, and Parkinson's. The group
studied trends in mortality rates due to diseases that are associated
with aging (e.g., diabetes, Alzheimer's, Parkinson's, diabetes, and
cerebrovascular disease), as well as HIV. They found strong parallels
between age-adjusted increases in death rates from Alzheimer's,
Parkinson's, and diabetes, and the progressive increases in human
exposure to nitrates, nitrites, and nitrosamines through the use of
processed and preserved foods as well as fertilizers. Other diseases
including HIV-AIDS, cerebrovascular disease, and leukemia did not
exhibit those trends. The authors propose that the increase in exposure
plays a critical role in the cause, development, and effects of the
pandemic of these insulin-resistant diseases.

Nitrites and nitrates belong to a class of chemical
compounds that have been found to be harmful to humans and animals. More
than 90% of them have been determined to be carcinogenic in various organs.
Nitrosamines are formed by a chemical reaction between nitrites or other
proteins. Nitrosamines become highly reactive at the cellular level, which
then alters gene expression and causes DNA damage. The investigators propose
that the cellular alterations that occur as a result of nitrosamine exposure
are fundamentally similar to those that occur with aging, as well as
Alzheimer's, Parkinson's, and type 2 diabetes mellitus.

Lead author Suzanne de la Monte, MD, MPH, of Rhode
Island Hospital says, “All of these diseases are associated with
increased insulin resistance and DNA damage. Their prevalence rates have
all increased radically over the past several decades and show no sign
of plateau. Because there has been a relatively short time interval
associated with the dramatic shift in disease incidence and prevalence
rates, we believe this is due to exposure-related rather than genetic

“Not only do we consume them [chemicals] in processed
foods, but they get into our food supply by leeching from the soil and
contaminating water supplies used for crop irrigation, food processing,
and drinking.”

The study findings indicate that while
nitrogen-containing fertilizer consumption increased by 230% between
1955 and 2005, its usage doubled between 1960 and 1980, which just
precedes the insulin-resistant epidemics the researchers found. They
also found that sales from the fast-food chains and the meat-processing
industry increased more than eightfold from 1970 to 2005, and grain
consumption increased fivefold.

The article states that the time frame of the
increased prevalence rates of Alzheimer's, Parkinson's, and diabetes
cannot be explained on the basis of gene mutations but, instead, mirror
classic signs of exposure-related disease. Because nitrosamines produce
biochemical changes within cells and tissues, it is conceivable that
chronic exposure to low levels of nitrites and nitrosamines through
processed foods, water, and fertilizers is responsible for the current
epidemics of these diseases and the associated increasing mortality

Special tattoo ink could monitor diabetes
In February, Massachusetts-based Draper Laboratories announced the development of a nano ink particle that constantly samples glucose levels in the skin. Injected subcutaneously, the ink changes color in response to glucose content in the skin. The idea behind the special tattoo ink is to eliminate painful blood-glucose tests for diabetics. According to a Draper scientist, the tattoo would only have to be a few millimeters in size and would not have to go as deep as a normal tattoo.

A yellow appearance indicates excess glucose. If the ink
turns purple, glucose levels are low. A healthy level of glucose is orange.
The sampling process repeats itself every few milliseconds.

The Draper team did not set out to create a
glucose-detecting ink. Originally, they developed a sodium-sensitive ink
to monitor heart health, advancing basic knowledge of electrolytes in
the body, or to ensure athletes are properly hydrated.

Researchers say it will, however, take at least two years before this
tattoo ink reaches the market.

Rare diabetes mainly affects men

News from Scotland in July recorded the significant
discovery by scientists at Biomedical and Life Sciences-Glasgow in their
study of a rare form of diabetes which usually affects men. Hereditary
diabetes insipidus is the most common genetic disease known in medicine,
say experts. It causes serious kidney malfunction and, if untreated, can
be fatal. In the United Kingdom, estimates of the number of hereditary
diabetes insipidus patients ranges around 9,000.

While the genetic basis of the disease has been
established for several years, researchers have now found an approach to
treatment that may pave the way for future drug development; current
strategies used for treatment have limited effect. Their report has been
published in Proceedings of the National Association of Sciences
of the USA (PNAS). The gene that is responsible for hereditary diabetes
insipidus is found on the X chromosome, which is why it is a
predominantly male condition.