SAN DIEGO – The annual incidence of new trunk varicose veins in adults during 13 years of follow-up is 1.36% results from a large study showed.
There were no differences in the annual incidence rate between men and women, but the risk of developing new trunk varicose veins increased significantly with age. The annual incidence of new trunk varicose veins also rose steadily with increasing BMI, but did not reach significance, perhaps because of the size of the study.
Dr. Lindsay A. Robertson
Those are key findings from the Edinburgh Vein Study, one of the first efforts to longitudinally measure the adult incidence of trunk varicose veins and to examine factors which increase the risk of varicose veins.
"There have been several studies conducted throughout the world, which have looked into the prevalence of varicose veins and associated risk factors, but few have examined new disease," Dr. Lindsay A. Robertson said at the annual meeting of the American Venous Forum. "While it is important to know about the prevalence of varicose veins, the design of studies is such that we cannot differentiate between the cause and effect. Therefore, it is important to start with people free of venous disease, [and] look at the risk factors, and then we can determine the true effect of such risk factors on the development of venous disease."
The Edinburgh Vein Study was a population cohort study conducted from 1994 to 1996 in a random sample of 1,566 citizens of Edinburgh, who were between the ages of 18 and 64 years. Dr. Robertson of the University of Edinburgh and her associates invited survivors of that cohort to participate in a 13-year follow-up examination, which included clinical classification of venous disease using CEAP, a duplex scan of leg veins, and measurements of height and weight, as well as a questionnaire for lifestyle risk factors such as mobility at work, smoking, pregnancy, previous treatment for varicose veins, and family history.
From baseline there were 1,446 survivors. Of those, 880 took part in the follow-up study, for a response rate of 60.4%. Of these, 490 were women and 390 were men. Their mean age was 60 years.
Dr. Robertson presented findings from 555 of the 880 participants who had no trunk varicose veins at baseline. Of these 555 participants, 101 developed grade C2 trunk varicose veins in any leg during the 13-year follow-up, for an overall incidence rate of 18.2% and an annual incidence rate of 1.36%. The annual incidence in men and women was similar (1.31% and 1.39%, respectively).
The annual incidence of new trunk varicose veins rose significantly with age, rising 0.73% per year among those aged 18-34 years, 1.23% among those aged 35-44 years, 1.62% among those aged 45-54 years, and 1.93% among those aged 55-64 years.
The annual incidence of new trunk varicose veins also rose steadily with increasing BMI, rising 1.06% per year among those who were underweight, 1.28% among those who were normal weight, 1.41% among those who were overweight, and 1.54% among those who were obese. These differences did not reach statistical significance, "but it’s thought that with higher numbers [of participants], these differences would reach statistical significance," Dr. Robertson said.
An association between the development of new trunk varicose veins and pregnancy was also observed. For example, the annual incidence of new trunk varicose veins was 1.24% among women who had never been pregnant, compared with 2.04% among women who had been pregnant at least four times. This finding was "borderline statistically significant," she said. "But with higher numbers of participants in each group, it’s thought that this would reach statistical significance."
The annual incidence of new varicose veins among participants who reported having a family history of varicose veins (defined as having a mother or father with the condition) was significantly higher compared with those who reported no family history of the condition (1.74% vs. 1.14%, respectively).
There was no significant difference in the annual incidence of new trunk varicose veins among those who reported a history of smoking at baseline compared with those who said that they never smoked (1.32% vs. 1.40%, respectively).
The cumulative incidence of new trunk varicose veins at follow-up was 13% among those who had no reflux at baseline, 23% among those who had deep reflux at baseline, 35% among those who had superficial reflux at baseline, and 42% among those who had deep and superficial reflux at baseline.
The study was funded by Scotland’s Chief Scientist Office. Dr. Robertson said that she had no relevant financial disclosures to make.