NEW YORK - Overweight middle-aged men may have a higher risk of heart problems and strokes and die earlier than their thinner peers -- even in the absence of some traditional risk factors, a new study suggests.

Some past research has suggested that when obese and overweight adults do not have the so-called metabolic syndrome, their risks of diabetes, heart disease and stroke are no higher than those of normal-weight people.

Metabolic syndrome refers to a collection of risk factors for diabetes and heart problems -- including abdominal obesity, high blood pressure, elevated blood sugar, low levels of "good" HDL cholesterol and high triglycerides (another type of blood fat). It is typically diagnosed when a person has three or more of those conditions.

In the current study, which followed more than 1,700 Swedish men for 30 years, overweight and obese men had increased risks of conditions including heart attack and stroke, even when in the absence of metabolic syndrome.

Among all men without metabolic syndrome, those who were overweight were 52 percent more likely to have heart attacks, strokes, and other complications than normal-weight men were, while obese men had nearly double the risk.

The findings are published in the American Heart Association journal Circulation.

"Our study shows that overweight (and) obese men without the metabolic syndrome are at higher risk" for heart disease, stroke, and other related conditions, study leader Dr. Johan Arnlov, of Uppsala University in Sweden, told Reuters Health by email. "This is in contrast to some previous studies that have suggested that obesity in the absence of the metabolic syndrome is a 'healthy' condition."

The study does, however, point up the added threat of having metabolic syndrome.

Obese men with metabolic syndrome had the highest risks -- showing 2.5 times the risk of heart disease and stroke, and related conditions, and of death, during the study period as men who were normal-weight and free of metabolic syndrome at the outset.

In addition, metabolic syndrome was harmful for normal-weight men as well; those with the condition were 63 percent more likely to develop heart disease, stroke, and related conditions than their counterparts who were free of metabolic syndrome.

According to Arnlov, the findings suggest that weight loss should be a goal for heavy men, regardless of whether they have metabolic syndrome. At the same time, being thin does not mean equate to a healthy heart -- though, Arnlov pointed out, metabolic syndrome is much more common among overweight people.

The findings are based on 1,758 men who, at the outset, were 50 years old and free of diabetes and previous hospitalizations for heart disease, stroke, and related conditions. Of the 955 normal-weight men, 64 had metabolic syndrome, as did 125 of 707 overweight men, and 66 of 96 obese men.

Over the next 30 years, 681 men suffered a heart attack, stroke or other major related complication. A total of 845 died.

Heavy men without metabolic syndrome had increased risks of such complications and death even with age, smoking and levels of "bad" LDL cholesterol taken into account.

It is not entirely clear why overweight men were at increased risk, but one issue the study did not address was physical fitness, AHA spokesman Dr. Barry Franklin noted in the news release from the heart association.

He suggested that as a "New Year's resolution," overweight adults recognize that there are health benefits to be gained from shedding even a few pounds through diet changes and exercise.

Arnlov said that future studies should look at whether similar findings are seen in women. However, he added, "I don't think we should consider obesity without the metabolic syndrome to be benign in women just because we don't have the data yet."