High BMI and Waist to Hip Ratio Forebodes Ill Health as Well as Early Demise

European scientists have found that having a large waistline can almost double a person’s risk of dying prematurely, regardless of their body mass index (BMI) being ‘normal’ or ‘above normal’. Furthermore, they implore that while assessing risk of death, waist size or waist to hip ratio should be taken into consideration.

The results of a study, conducted by researchers from Imperial College London, the German Institute of Human Nutrition, and other research institutions across Europe, was published in the New England Journal of Medicine on the 13th of November.

The researchers marked that the preceding studies relied heavily on a person’s BMI to assess the link between body fat (adiposity) and the risk of death with complete disregard for the effect of distribution of body fat.

Researchers used data from a study conducted by the European Prospective Investigation into Cancer and Nutrition (EPIC) on 359,387 participants from 9 countries. In Termed, the largest long-term prospective study in the world, the mean age of the participants was 51.5 years at the onset of the study, and 65.4% of the participants were women.

The researchers explored links between BMI, waist circumference, and waist-to-hip ratio with risk of death. Moreover, they took into account other factors like age, location, education, smoking, alcohol, exercise and the height of each participant. In order to successfully conclude their research, the investigators used a statistical tool called the ‘Cox regression analysis’.

The results confirmed that 14,723 of the participants died over a mean follow up period of 9.7 years. Therefore it can be concluded that:

• Participants with a high BMI, compared with those in the medium range, were more likely to die from cardiovascular diseases and cancer.
• Participants with a low BMI were more likely to die from respiratory diseases.
• BMI of 25.3 for men and 24.3 for women was linked to the lowest risk of death.
• After taking BMI into account, waist circumference and waist-to-hip ratio were strongly linked to risk of death.

Besides, this study also brought forth facts like:

• The 20% of participants with the largest waist circumferences (top quintile) had waistlines measuring more than 120cms (47.2 in) for men and 100cms (39.4 in) for women.
• The 20% with the smallest waist circumferences (bottom quintile) had waists smaller than 80cms (31.5 in) for men and 65cms (25.6in) or less for women.
• For every 5cm increase in waist circumference the risk of death went up by 17% in men and 13% in women.
• The top quintile for men had a relative risk of death of 2.05 (95% confidence interval (CI) of 1.80 to 2.33) while for women this figure was 1.78 (95% CI 1.56 to 2.04).
• For waist to hip ratio the top to bottom quintile relative risks were 1.68 (95% CI 1.53 to 1.84) for men and 1.51 (95% CI 1.37 to 1.66) for women.

The results of the initial findings further supported the fact that BMI is strongly linked to risk of death. The authors additionally explained that the “BMI remained significantly associated with the risk of death in models which included waist circumference or waist-to-hip ratio (P < 0.001)”.

In addition, it has been concluded that these findings suggest that both general fat and abdominal fat are associated with the risk of death. This finding further supports the use of waist circumference or waist -to-hip ratio in addition to BMI to correctly assess the risk of death.

Furthermore, the study strongly evidences the fact that a significantly larger waist to hip ratio poses a significant health risk, even in people who are not considered to be overweight or obese. Moreover, they insist that doctors measure waistlines and hips as well as BMI when doing routine health checks. The researchers have also concluded that the waist to hip ratios vary widely among different countries in Europe.

The reason that increased waistlines are linked to higher risk of death is because the fatty tissue in the abdomen secretes cytokines, hormones and chemicals that are known to increase the risk of chronic diseases such as cardiovascular diseases and cancer.

Lead author and a Private Docent at the German Institute of Human Nutrition in Potsdam-Rehbrücke, Dr Tobias Pischon, elucidated that abdominal fat apart from being an energy depot, it also releases messenger substances that can contribute to the development of chronic diseases.

Professor Elio Riboli, from the Department of Epidemiology and Public Health at Imperial College London and the European coordinator for EPIC, said that it was surprising to see the waist size having such a powerful effect on people’s health and premature death, although very small studies have suggested a link between mortality and waist to hip ratio. He also said that smoking and drinking as well as other individual characteristics increase the likelihood of early death.

Some researchers further state that genetic factors, inactive lifestyles and poor diets are also responsible for larger waistlines.

Riboli has further affirmed that it costs virtually nothing to measure one’s waist and hip size and that people with large waists should exercise every day, avoid drinking too much alcohol and improve their diet. A small step in the right direction could dramatically reduce one’s risk of early death.