Millions of middle-aged adults who are overweight with even slightly raised blood pressure, cholesterol or glucose levels are about a third more likely to die early, research suggests.
They also face a 35% higher risk of heart attacks or strokes and will experience them two years earlier than their peers. The stark findings are being presented at the annual meeting of the European Society of Cardiology, the world’s largest heart conference. They represent more evidence of the immediate dangers posed by the global obesity crisis.
It is estimated that up to 31% of the global population has metabolic syndrome, although many will have no idea and remain undiagnosed.
Metabolic syndrome is the medical term for having three or more unhealthy traits, including being very overweight or having too much fat around your waist, high blood pressure, high cholesterol or high glucose levels.
“Many people in their 40s and 50s have a bit of fat around the middle and marginally elevated blood pressure, cholesterol or glucose but feel generally well, are unaware of the risks and do not seek medical advice,” said the study author Dr Lena Lönnberg of Västmanland county hospital in Västerås, Sweden.
“This scenario, called metabolic syndrome, is a growing problem in western populations where people are unknowingly storing up problems for later in life. This is a huge missed opportunity to intervene before heart attacks and strokes that could have been avoided occur.”
Previous studies have shown that people with metabolic syndrome are at higher risk of diabetes, heart disease, stroke and premature death. This study investigated the link between asymptomatic metabolic syndrome in middle age and cardiovascular disease and death up to three decades later.
The study enrolled 34,269 adults in their 40s and 50s who attended a cardiovascular screening programme in 1990 to 1999 in the Swedish county of Västmanland. Participants went to their primary health care centre for a clinical examination by a nurse, which included measurements of height, weight, blood pressure, total cholesterol, blood glucose, and waist and hip circumference.
They also completed a questionnaire about lifestyle habits, previous history of cardiovascular disease and diabetes, and socioeconomic factors such as education.
People were classified as having metabolic syndrome if they had three or more of the following: a waist circumference of 102cm (40in) or above for men and 88cm (34in) or above for women, a total cholesterol 6.1mmol/l (millimoles per litre of blood) or above, 130 mmHg (millimetres of mercury) or higher systolic blood pressure and/or 85 mmHg or higher diastolic blood pressure, and fasting plasma glucose 5.6mmol/l or higher.
The researchers analysed the associations between midlife metabolic syndrome and non-fatal cardiovascular events and all-cause mortality after adjusting for age, sex, smoking, physical inactivity, education level, body mass index, hip circumference and living alone or with family.
A total of 5,084 individuals met the criteria for metabolic syndrome and a control group of 10,168 individuals without metabolic syndrome was identified; 47% of participants were women.
During a median follow-up of 27 years, 1,317 (26%) participants with metabolic syndrome died compared with 1,904 (19%) controls – meaning those with metabolic syndrome were 30% more likely to die during follow-up than their counterparts without metabolic syndrome.
Non-fatal heart attacks or strokes occurred in 1,645 (32%) participants with metabolic syndrome and 2,321 (22%) controls – corresponding to a 35% greater risk of heart attack and stroke in the metabolic syndrome group. The median time to the first non-fatal heart attack or stroke was 16.8 years in the metabolic syndrome group and 19.1 years in the control group – a 2.3 year difference.
Lönnberg said: “As metabolic syndrome is a cluster of risk factors, the level of each individual component does not have to be severely raised. In fact, most people live with slightly raised levels for many years before having symptoms that lead them to seek health care.
“In our study, middle-aged adults with metabolic syndrome had a heart attack or stroke 2.3 years earlier than those without the collection of unhealthy traits. Blood pressure was the riskiest component, particularly for women in their 40s, highlighting the value of keeping it under control.”
Prof Sir Nilesh Samani, medical director at the British Heart Foundation, said: “Even if you feel fine, small increases in your blood pressure, waist measurement, cholesterol and blood sugar can have a substantial impact on your future risk of heart attacks and strokes.
“The important message is that it is possible to reduce your risk through simple measures. Eating well-balanced meals, regular physical activity, and not smoking can all help to lower your blood pressure and cholesterol and your control weight.
“If lifestyle changes aren’t enough, your GP can also advise on medication that can help to reduce your risk.”
