Monday, January 28, 2013

Dubious Canadian findings about diabetes and income

The findings below are far from surprising but they are also  poorly substantiated.  Results given in extreme quintiles are intrinsically uninteresting because they throw away most of the data -- and in this case even the quintile differences reported were slight.  It almost goes without saying that there was no overall relationship between the variables in the study. 

And switching to quartiles for other analyses tells us pretty clearly that the researchers were determined to find something to report in data where there was essentially nothing to report.  I conclude that income did NOT influence diabetes in the data concerned.

The journal article is "The impact of income on the incidence of diabetes: A population-based study" by Lysy, Z. et al..  I am not entirely sure why I am commenting on such rubbish

Canadian researchers have found that diabetes incidence is inversely related to income in the province of Ontario.

"Study of the Ontario population has already shown significant mortality difference in patients according to income in patients with diabetes," say Lorraine Lipscombe (Women's college Research Institute, Toronto) and team. "We now see that this is the population for whom the relative risk of developing diabetes is the greatest as well."

However, the income disparity was not equal in all populations, with women and younger people (aged under 40 years) the most vulnerable to developing the condition.

Diabetes prevention should be targeted to appropriate populations and healthcare costs should be budgeted to support younger and female lower-income populations, suggest Lipscombe and colleagues.

In an analysis of healthcare databases, the researchers found that between April 2006 and March 2007, 88,886 new cases of diabetes were identified in Ontario, with a mean age at diagnosis of 59 years.

Diabetes incidence was significantly higher among individuals from the lowest versus the highest quintiles for income, at rates of 8.70 versus 7.25 per 1000 people.

Multivariate analysis also showed that diabetes incidence was significantly higher among individuals from lowest versus highest quintiles for income, a trend that was seen across all age groups and in both males and females.

However, as reported in Diabetes Research and Clinical Practice, significant interactions were observed between income quintile and age groups. Among younger people from the lowest quartile for income, the risk for incident diabetes was 1.5 times higher than in those from the highest quintile for income. This difference narrowed with increasing age, with those aged 40-59 years at a 1.38-fold greater risk and those aged 60 or older at a 1.2-fold greater risk.

The finding that the income gap is more marked in younger people is "alarming" say the researchers, "given their longer lifetime duration of disease and potential complications."

"These patients will require long-term intensive health care to avoid complications, and financial barriers may impede adequate access to diabetes treatment and monitoring," they add.

The team also found that women experienced a wider gap in relative risk for diabetes according to income across all age groups, while in men, the gap narrowed with increasing age.

"Greater diabetes prevention efforts need to be directed toward younger and female, low-income populations in order to lessen the lifelong burden of diabetes on the health and productivity of an already disadvantaged population," concludes the team


A Mediterranean diet WON'T stave off dementia or boost concentration in old age

A Mediterranean diet does little for the brain and won't prevent dementia, researchers claim.  French scientists say there is no evidence that eating plenty of fruit, vegetables and oily fish boosts concentration in old age.

Inspired by traditional eating habits in Italy, Spain and Greece, the diet has been shown to prevent heart disease and cancer as well as increase life expectancy. And recently a number of studies have implied it may be just as beneficial for the brain and could stave off Alzheimer's.

Some scientists believe that because the diet is low in saturated fat, it prevents the blood vessels that supply the brain becoming blocked.

But academics from Paris Sorbonne University say there is no evidence for such a link.

The researchers tracked the diets of 3,000 middle-aged adults for more than a decade and divided them into three groups depending on how `Mediterranean' their diet was.

When the adults were 65 and over, they took six tests which checked their concentration and memory.

The results, published in the American Journal of Clinical Nutrition, found no difference between the scores of the three groups.

Lead researcher Emmanuelle Kesse-Guyot said: `Midlife adherence to a MedDiet was not associated with global cognitive performance [brain power assessed 13 years later].'

Furthermore the researchers said that recent work by other  scientists had also failed to find any link.

Last year, the Foundation for Public Health in Paris found  women over 65 who followed a Mediterranean diet did not perform any better in memory tests.

However, Professor Nikos Scarmeas, from the Columbia University Medical Centre in New  York, said there was not yet enough evidence to draw firm conclusions about the diet's  effect on the brain.  [Old myths die hard]


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