Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Waist-hip ratio should replace body mass index as indicator of mortality risk in older people

08.08.2006
Older people with high waist-hip ratios (WHRs) have a higher mortality risk than those with a high body mass index, or BMI, a new study reveals.

Whereas justifiable attention is given to the increasing problem of obesity in the general population, far less is known about the relationship between obesity and mortality in older people, or how mortality risk should be estimated. The excess health risks associated with having a high BMI are known to decline with age, yet expert bodies such as the National Institutes of Health and the World Health Organisation have continued to use in older people the same BMI criteria as for other age groups.

Today’s study, published in the American Journal of Clinical Nutrition, was carried out by a team based at the London School of Hygiene & Tropical Medicine. It sought to investigate the association of BMI, waist circumference (WC) and WHR with mortality and cause-specific mortality. The researchers studied 14,833 patients aged over 75 from 53 family practices in the UK; the subjects underwent a health assessment that included taking body measurements and a follow-up (with a median of 5.9 years) for mortality.

The findings confirmed that the current guidelines for BMI-based risk categories overestimate the risks of excess weight in people aged over 75 and are inappropriate for older men and women. This concurs with a previous study that found BMIs of 25-27 not to be a risk factor for all-cause and cardiovascular mortality in those aged 65 and over 1. Most consistently, the data highlighted the risk of having a low BMI, with people in the lowest quintile (less than 23 in men and less than 22.3 in women) demonstrating the highest risk of death for total mortality and for major causes of death. Very underweight men (those with a BMI of under 18.5) were found to be particularly at risk.

‘An explanation for the lack of a positive association with BMI and mortality at older ages is that, in older persons, BMI is a poor measure of body fat’, say the authors. ‘The measurement of weight does not differentiate between fat and fat-free mass, and fat-free mass (especially muscle) is progressively lost with increasing age

Waist circumference (WC) has been proposed as an alternate or additional measure of obesity. The study found no association with waist circumference and mortality. The authors continue: ‘A limitation of WC alone as a measure is that it takes no account of body composition, whereas WHR is a measure of body shape and to some extent of lower trunk adiposity [abdominal fat]. Although it is possible theoretically for high WHR to coexist with thinness, our data show that those with high WHR had higher-than-average waist and average hip circumferences. We conclude that the association observed for WHR and mortality is probably explained by abdominal adiposity’.

The authors recommend that the current BMI-based health risk categories to define the burden of disease related to adult overweight and obesity be reviewed, as they are not appropriate for those over 75. They suggest that WHR should instead be used in this age group because of its positive relation with risk of death, and that attention should also be paid to the problem of underweight in old age.

To interview the authors, please contact the London School of Hygiene & Tropical Medicine Press Office on 020 7927 2073.

Lindsay Wright | alfa
Further information:
http://www.lshtm.ac.uk

More articles from Studies and Analyses:

nachricht New study from the University of Halle: How climate change alters plant growth
12.01.2018 | Martin-Luther-Universität Halle-Wittenberg

nachricht Disarray in the brain
18.12.2017 | Universität zu Lübeck

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Optical Nanoscope Allows Imaging of Quantum Dots

Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together with colleagues from the University of Bochum, scientists from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute reported the findings in the journal Nature Photonics.

Microscopes allow us to see structures that are otherwise invisible to the human eye. However, conventional optical microscopes cannot be used to image...

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Physicists have learned to change the wavelength of Tamm plasmons

24.01.2018 | Physics and Astronomy

When the eyes move, the eardrums move, too

24.01.2018 | Health and Medicine

Deaf children learn words faster than hearing children

24.01.2018 | Health and Medicine

VideoLinks Science & Research
Overview of more VideoLinks >>>