Genes controlling insulin ‘alter’ body clock

Washington, Sept 18 (ANI): Scientists at University of California, San Diego have identified certain insulin-regulating genes that can also alter the timing of the body clock.

They said that the findings can lead to new approaches to treating disorders such as metabolic syndrome that can result, at least in part, from chronic disruption of the sleep-wake cycle.

“People knew that the clock regulates many different processes, but what they didn’t realize what that when you tweak those processes, it feeds back and alters the clock,” said Steve Kay, Dean of the Division of Biological Sciences at the University of California, San Diego, who led the study along with John Hogenesch of the University of Pennsylvania.

A molecular clock controls daily physiological rhythms in many types of cells, even cells grown in culture.

By engineering cultured cells to glow yellow when a particular clock gene switched on, the team made the cycle visible. They then interfered with every human gene to see which would shift the clock. They found that hundreds altered the timing.

“We just suddenly discovered 350 new genes that affect the clock that weren’t known before,” Kay said.

However, subsequent screening to confirm the genes’ effect on a second clock gene narrowed the list to 200.

Seven genes involved in insulin control also influenced the rhythms of the clock.

“What came out very strongly was this close relationship between circadian regulation and insulin signalling. There’s a reciprocal relationship between circadian dysfunction and metabolic dysfunction,” said Kay.

The researchers suggest that genetically altered mice with malfunctioning clocks become obese and develop diet-induced diabetes.Understanding this close relationship between circadian regulation and metabolic homeostasis should provide novel ways of identifying new therapies for metabolic disease,” Kay added.

The study appears in journal Cell. (ANI)

Fat in liver, not belly, could determine heart disease risk

Washington, Aug 25 (ANI): Measuring liver fat may be a better way to determine a person’s risk for developing diabetes and heart disease than measuring belly fat, according to researchers at Washington University School of Medicine in St. Louis.

Having too much liver fat is known as nonalcoholic fatty liver disease.

The researchers say that when fat collects in the liver, people experience serious metabolic problems such as insulin resistance, which affects the body’s ability to metabolize sugar.

They also have increases in production of fat particles in the liver that are secreted into the bloodstream and increase the level of triglycerides.

For years, scientists have noted that where individuals carried body fat influences their metabolic and cardiovascular risk.

Increased fat inside the belly, known as visceral fat, is linked to an higher risk of diabetes and heart disease.

“Data from a large number of studies shows that visceral fat is associated with metabolic risk, which has led to the belief that visceral fat might even cause metabolic dysfunction,” says study’s lead author Samuel Klein.

“However, visceral fat tracks closely with liver fat. We have found that excess fat in the liver, not visceral fat, is a key marker of metabolic dysfunction. Visceral fat might simply be an innocent bystander that is associated with liver fat,” he added.

Klein says most of our body fat, called subcutaneous fat, is located under our skin, but about 10 percent is present inside the belly, while much smaller amounts are found inside organs such as the liver and muscle.

In the study, the researchers compared obese people with elevated and normal amounts of liver fat. All subjects were matched by age, sex, body mass index; percent body fat and degree of obesity.

Through careful evaluations of obese people with different amounts of visceral fat or liver fat, Klein’s team determined that excess fat inside the liver identifies those individuals who are at risk for metabolic problems.

The study has been published online in the journal PNAS Early Edition. (ANI)

Patients with lower urinary tract symptoms ‘at increased metabolic syndrome risk’

Washington, June 20 (ANI): A new study has revealed that patients with severe to mild lower urinary tract (LUT) symptoms are at a greater risk of developing metabolic syndrome, a collection of cardiovascular risk factors.

“These findings have important diagnostic and management implications,” said the authors.

“Patients who present with components of metabolic dysfunction should be routinely queried with respect to urological function, particularly voiding symptoms such as intermittency, incomplete emptying and nocturia, as well as the degree of associated bother.

“Sexual dysfunction symptoms, particularly erectile dysfunction, are similarly reported by the majority of men with MetS and should be routinely evaluated,” they added.

During the study, the researchers interviewed 2,301 men 30 to 79 years old. They found an increased odds ratio of 1.68 for metabolic syndrome was observed in men with mild to severe LUTS symptoms compared to those with few or no symptoms.

They also found increased odds of the metabolic syndrome even with mild symptoms, primarily for incomplete emptying, intermittency and nocturia.

The study appears in The Journal of Urology. (ANI)