A difference was found in the change of BMI between the study group and the control group during the follow-up time. In the study group the increase rate was higher and it was constant over the follow-up time, whereas in the control group the rate slowed slightly during the last 5
years of the follow-up. This suggests that the effects of the PHE had not been efficient enough to stop the weight gain in either group. Especially in the study group the remarkable increase in BMI was seen despite the PHE conducted during the follow-up time and there were no signals of weight gain slowing down.
The subjects in the study group had a higher level of BMI at baseline. Because obesity in known to be a major risk factor for cardiovascular disease and diabetes, the subjects in the study group were in greater risk already on that basis compared with the control group at the very beginning. In that sense it would have been possible to allocate the preventive actions to these subjects in the PHEs. The result suggests that PHE could not intervene with the weight gain of subjects who had a high risk to cardiovascular disease and diabetes.
The increase in blood pressure was in high extent consistent with that of BMI. The blood pressure (both systolic and diastolic) was at higher level in the study group than in the control group already at baseline. The increase in systolic blood pressure was also greater in the study group than in the control group between the ages of 40 and 45. Favorable effects of PHE were not seen in relation to changes in blood pressure, even though blood pressure medication had been started for more than half of the subjects in the study group.
Participant views of the PHE in Tampere have been previously examined in 1995, in a 45-year-old cohort [12
]. According to the participants' accounts, the discussions and counseling with a public health nurse had dealt with living habits and, to a lesser extent, with diseases, symptoms and the prevention of illness. Virtually all respondents saw the PHE program as beneficial for everyone. Opinions were divided on its benefits compared with medical help from a physician. Looking at the present results, the PHE, conducted at 5-year intervals by a public health nurse, had not been very effective in intervening with living habits, since BMI continued to increase in the study group, who were already at risk at the age of 35
years. It has been reported that adults who were overweight but not obese (i.e., 25.0
29.9) were at significantly increased risk of developing numerous health conditions, such as diabetes, gallstones, hypertension, heart disease, and stroke [6
]. Although the study group had a diagnosis of diabetes or hypertension by a physician, their medical intervention was not sufficient in terms of blood pressure medication. Certainly a larger proportion of cases would have been in need for more regular intervention and medication.
At the age of 35, subjects in the study group used more alcohol per week (95
g) than controls (79
g). This alcohol consumption should be considered in the context that self-reporting of drinking is commonly unreliable and the official per capita mean consumption of absolute ethanol in Finland for inhabitants 15
years and older is 8.4
l per year, corresponding to 162
g per week [13
]. Since physical activity was not different between the study group and controls, the difference in alcohol intake has potential to explain the remarkable increase of BMI in the study group compared to controls during the follow-up time.
The strength of present study is the large cohort from which the data was collected. The data analyzed included 943 subjects all born in the four year period 1951–54 and followed up for 15
years. Thus there was no confounding by age. The 15-year follow-up of the cohort enables to study trends in health factors. However, since the study group was restricted to residents of a large city in Finland poses a challenge to how broadly one can apply the findings. Because the studied population represented only Caucasians, our findings cannot be generalized to minority groups.