Factbox: Findings of global study on obesity, heart risks

(Reuters) - Worldwide rates of obesity have nearly doubled since 1980, but rich Western nations have made good progress in lowering hypertension and cholesterol, according to a large study of key heart disease risk factors.

Here are some key facts and the main findings of the research, which was published in The Lancet medical journal.

BODY MASS INDEX (BMI)

* BMI is measured as weight in kilograms divided by height in meters squared, or by dividing weight in pounds by height in inches squared and multiplying by 703. A person 5 feet 5 inches tall is classified as overweight at 150 pounds (68 kg) and obese at 180 pounds (82 kg).

* Being overweight or obese raises the risk of heart disease, diabetes, some cancers, arthritis and other conditions.

FINDINGS:

- In 2008, 9.8 percent of men and 13.8 percent of women in the world were obese (with a BMI above 30), compared with 4.8 percent for men and 7.9 percent for women in 1980.

- Pacific island nations have the highest average BMI in the world, reaching 34-35, up to 70 percent higher than some countries in Southeast Asia and sub-Saharan Africa.

- Among high-income countries, the United States has the single-highest BMI (over 28 for both men and women), followed by New Zealand. Japan has the lowest BMI (22 for women and 24 for men), followed by Singapore.

- Among high-income countries, between 1980 and 2008, BMI rose most in the United States (by more than 1 point per decade), followed by New Zealand and Australia for women and followed by the UK and Australia for men. Women in a few Western European countries had virtually no rise in BMI.

- The UK has the sixth-highest BMI in Europe for women and ninth-highest for men (both around 27). Turkish women and Czech men have the highest BMI in Europe (both around 28). Swiss women had the lowest BMI in Europe (around 24).

BLOOD PRESSURE:

* High blood pressure, or too much force exerted by blood as it moves against vessel walls, is the leading risk factor for premature death worldwide. It raises the risk of stroke, heart attack, heart failure and other conditions. Simple steps like exercise and a low-sodium diet can help lower hypertension

* Blood pressure is measured in millimeters of mercury or mmHg. Normal systolic blood pressure -- the top blood pressure number -- is considered to be 120 mmHg. The borderline range is 120-139 mmHg and high blood pressure is 140 mmHg and over.

FINDINGS:

- Systolic blood pressure is highest in Baltic and East and West African countries, reaching 135 mmHg for women and 138 mmHg for men. These levels were seen in some Western European countries in the 1980s before their recent declines.

- South Korea, Cambodia, Australia, Canada and the United States had some of the lowest blood pressures for both men and women, below 120 mmHg for women and below 125 mmHg for men.

- Among high income countries, Portugal, Finland and Norway have the highest blood pressure.

- Men had higher blood pressure than women in most world regions.

CHOLESTEROL:

* Cholesterol levels are measured in milligrams of cholesterol per deciliter (mg/dL) of blood in the United States and some other countries and in millimoles per liter (mmol/L) of blood in Canada and most European countries.

* Total cholesterol levels of below 200 mg/dL (5.2 mmol/L) is considered desirable.

* When cholesterol is too high, it can cause a buildup of fatty deposits in the arteries that can rupture, raising the risk for heart attack, stroke, circulation problems and death.

* A recent World Health Organization report found that most people with high cholesterol levels do not get the treatment they need. Cholesterol-lowering drugs called statins, which include Pfizer's Lipitor and AstraZeneca's Crestor, lower levels of harmful blood fats.

FINDINGS:

- Western European countries like Greenland, Iceland and Germany have the highest cholesterol levels in the world, with average serum total cholesterol of around 212 mg/dl (5.5 mmol/L).

- African countries have the lowest total cholesterol, with some as low as 155 mg/dl (4 mmol/L).

- Among Western high-income countries, Greece has the lowest cholesterol for both men and women at below 193 mg/dl (5 mmol/L). The United States, Canada and Sweden also had low cholesterol.

- The UK's cholesterol is ninth-highest in the world, slightly below 212 mg/dl (5.5 mmol/L).

SOURCE: The Lancet/Reuters

(Compiled by Julie Steenhuysen and Kate Kelland, editing by Eric Beech)