“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 study author Dr. Lena Lönnberg of Västmanland County Hospital, 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.”
Recent estimates are that up to 31% of the global population has metabolic syndrome (2), studies have shown that those with metabolic syndrome are at an increased risk of stroke, heart disease, diabetes, and premature death (3-5); this study set out to investigate the link between metabolic syndrome in midlife and cardiovascular disease and death up to 30 years later.
This study involved 34,269 adults between the ages of 40-59 who attended a cardiovascular screening program, had a clinical examination, and completed questionnaires about their lifestyle habits, medical history, and socioeconomic factors such as job and education. Participants were classified as having metabolic syndrome if they had three or more of the following: 1) waist circumference of 102 cm or above for men and 88 cm or above for women, 2) total cholesterol 6.1 mmol/l or above, 3) 130 mmHg or higher systolic blood pressure and/or 85 mm Hg or higher diastolic blood pressure, 4) fasting plasma glucose 5.6 mmol/l or higher.
Participants with metabolic syndrome were matched with two individuals without metabolic syndrome who served as controls, and the researchers collected data on cardiovascular events and death from national and local registries. After adjusting for various factors that could influence their findings the researchers analyzed the associations between midlife metabolic syndrome and nonfatal cardiovascular events and all-cause mortality.
Of the 34,269 individuals, only 15% (5,084) met the criteria for metabolic syndrome, and a control group of 10,168 was identified. During a median follow-up of 27 years, 26% of the participants with metabolic syndrome died compared to 19% of the controls, suggesting that those with metabolic syndrome were 30% more likely to die during follow-up than their peers who were without metabolic syndrome. 32% of those with metabolic syndrome experience non-fatal cardiovascular events compared to 22% of the controls, meaning those with metabolic syndrome were 35% more likely to have a stroke or heart attack than their peers. Additionally, the median time to the first non-fatal cardiovascular event was 16.8 years in those with metabolic syndrome compared to 19.1 years in the control group, which is a 2.3-year difference.
“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,’ said Dr. Lönnberg.
The researchers concluded that “The results underline the importance of early detection of risk factors through health screening programmes so that preventive actions can be taken to prevent heart attack, stroke and premature death. As a general rule of thumb, even if you feel well, check your blood pressure every year, avoid smoking, keep an eye on your waist circumference and last, but definitely not least, be physically active every day.”
