Abstract
Aim: To evaluate the social performance of young adults with type 1 diabetes (T1D) since childhood with particular interest in its relation to the severity of diabetic retinopathy (DR). Methods: The prevalence of DR was evaluated in a population-based Finnish cohort of children with T1D during 1989–1990. The subjects were contacted 18 years later for evaluation of DR, education, employment, and family relations. Results: 136 of 216 subjects participated in the study in 2007 (mean age 30±3 years, mean diabetes duration 23±4 years, 78 men). There were 42 subjects (31%) with proliferative diabetic retinopathy (PDR). A university degree was held by 9%, a degree from a university of applied sciences by 33%, and 45% had a vocational school education; 7% were full-time students while 4% had received no education after comprehensive school. PDR was associated with lower education. Sixty percent of the subjects with PDR and 68% of those with non-PDR held full-time jobs. Four percent of the non-PDR group were unemployed while 26% of subjects with PDR were outside working life because of either unemployment or retirement. Seventy-one percent of the subjects had a spouse, and 60 subjects had a total of 119 children. PDR did not compromise the likelihood of having a spouse and children. Conclusions: The majority of young adults with T1D take active roles in society by working and raising families. However, patients with PDR lacked secondary education significantly more often and were less likely to work than those with non-PDR.
Keywords
Background
In Finland, the incidence of type 1 diabetes (T1D) is the highest in the world [1]. The age at onset has shifted towards younger children (0–4 years) in Finland and across Europe [1–3]. At adult age, the subjects with T1D are principally in the hands of primary health care in the Finnish health care system. This is true for both monitoring of glucose control as well as screening for diabetic complications, including fundus photography for detection of diabetic retinopathy (DR).
T1D has been associated with impaired cognitive function [4,5]. Hypoglycemic episodes, and possibly recurrent hyperglycemia, are thought to be the major contributors leading to structural and functional alterations in the brain [6,7]. Cognitive deficits related to T1D are often considered subtle and clinically insignificant [8]. However, young children with early-onset T1D (<5 years of age) demonstrate particular vulnerability to cognitive decrements [8,9]. According to a Finnish study, children with early-onset diabetes are more likely to experience minor learning difficulties during early school years [10]. The increased risk of learning problems also occurs independently of a history of severe hypoglycemia [11].
Academic performance amongst individuals with T1D is slightly less favorable than their non-diabetic peers [12]. In Sweden, school performance of children with T1D was evaluated at the level of compulsory education [13,14] and upper secondary school [14]. Pupils with T1D achieved slightly, but significantly, lower school marks than children without diabetes, both in compulsory schooling and in more advanced classes in upper secondary school [13,14]. It was clear that particularly children with early-onset diabetes (<2 years [13] and <5 years [14], respectively) were the most disadvantaged. Other studies have reported similar findings showing early onset of the disease resulting in lower academic achievement than later onset [9]. This raises concerns as an increasing number of children are diagnosed with T1D at an early age.
Chronic illness may have a negative effect on a patient’s quality of life (QoL) from early on [15,16]. In the Oulu cohort, health-related QoL of young adults with T1D was determined to be equal to that of healthy subjects as long as proliferative diabetic retinopathy (PDR) was not present, but the QoL was significantly lower in patients with PDR and associated vision-related problems [17].
The incidence of microvascular complications, including DR, increases with the duration of diabetes. Patients are usually asymptomatic during early stages of DR, while advanced DR may cause visual impairment. DR is very rare before puberty and during the first years after the onset of T1D [18,19]. Ophthalmic status can range after puberty from normal visual function with unaffected fundi in some individuals, to blindness due to florid DR in those with the most difficult course of the eye disease. Advanced DR can thus have a substantial impact on the life course and social opportunities of an individual.
With an increasing number of patients living with early onset T1D, it is important to be aware of the possible consequences related to health and overall performance, including an individual’s social status. In this study, the focus is on the social well-being of young adults with childhood-onset T1D in terms of education, employment, and family. The results will be beneficial and valuable for seeking further improvements in the diagnostics, treatment, and rehabilitation of children with T1D to achieve better social performance.
Methods
During 1989–1990 the prevalence of DR was evaluated in a population-based cohort of 5–16-year-old children with T1D (n=216) living in the catchment area of the Northern Ostrobothnia Hospital District, Finland. In 2007, we contacted the same patients and invited them to participate in a follow-up study. The study was carried out according to the Declaration of Helsinki, and the participants gave informed consent before participating. The Ethics Committee of the Northern Ostrobothnia Hospital District approved the study.
After enrolment, an outpatient visit was arranged at the Department of Ophthalmology of Oulu University Hospital. Reimbursements were made for travel expenses. An ophthalmic evaluation was performed by an ophthalmologist. All patients were asked to fill out a questionnaire concerning the year of graduation from the Finnish 9-year-long comprehensive school, education received after comprehensive school, working history and employment, marital status, number of children, and their year of birth.
The stage of DR was evaluated from 60° color and black-and-white fundus photographs. Trained technicians from the Department of Ophthalmology took the photographs with a digital mydriatic fundus camera (Canon CF-60DSi Digital Mydriatic Fundus Camera). Two ophthalmologists viewed and graded the images independently according to the classification of the Finnish National Guideline for Diabetic Retinopathy [20]. In case of a disagreement in grading, a third ophthalmologist re-evaluated the fundus photographs to determine the final classification of the subject. If the stage of DR differed between the eyes, the patient was classified according to the stage of the eye with more advanced DR. Twenty-eight of those who were not able to attend the eye examination filled out the questionnaire at home and returned it by mail. The DR stage is based on ophthalmology records from other institutions in those cases. The information on schooling, employment, and families was compared between the subjects with PDR (PDR group) and those with less severe or no retinopathy (non-PDR group). In terms of this paper, pension refers to a patient who has been retired on medical grounds.
Data are given as means and standard deviations or range. Fisher’s exact test and Mann–Whitney U test were used in the statistical analysis. A p-value <0.05 was considered statistically significant. SPSS (version 18.0, SPSS Inc., Chicago, IL, USA) was used in the analyses.
Results
The study comprised 136 subjects (mean age 30±3 years, 78 men) representing 63% of the original cohort. The mean duration of T1D was 23±4 years at the time of examination in 2007. The mean age of onset of T1D was 7±4 years (range 0.9–16 years). Forty-eight subjects had been diagnosed with T1D before 5 years of age. Eight (4%) patients of the original cohort of 216 had died and 72 (33%) could not be reached or did not wish to take part in the study.
Forty-two (31%) of the 136 patients (32% of men and 29% of women) had developed PDR. The non-PDR group consisted of 92 (68%) patients of which 85 (63%) had background DR and seven (5%) showed no sign of DR. Of the 48 subjects with early-onset T1D (<5 years), 17 (35%) had PDR while 26 (30%) of those with later-onset T1D were diagnosed with PDR. The age at onset of T1D did not differ statistically significantly between the subjects with PDR and the non-PDR group (p=0.865, Mann–Whitney U test). In two cases the stage of DR was not known.
Ninety-seven subjects (71%) were married or cohabiting, 31 (23%) were single and eight (6%) were divorced. Sixty subjects (44% of men and 45% of women) had a total of 119 children, 34 males having 77 children and 26 females having 45 children; three children belonged to a couple both of whom were taking part in this study. Twenty-seven subjects had one child, 26 subjects had two or three children and seven subjects had four or more children. In addition, five women and two men, one of whom had already had a child, were expecting a baby. Of the 60 with children, four (7%) had no DR and 20 (33%) had PDR. The figures were similar for those without children: no DR in three of the 76 (4%) and PDR in 22 of the 76 (29%), respectively. The subjects with PDR were equally likely to have a spouse (p=0.349) and children (p=0.580) as those with less severe or no DR.
The subjects of the study were married or cohabiting more often than the Finnish general population of their age. Both women and men were parenting children more commonly than the general population of 23–24 year olds and 25–29 year olds, but the proportion of 30–34 year olds with children appeared to be similar to the general population (Table I).
Family relations of the study subjects evaluated in 2007 and Finnish general population by age.
T1D= type 1 diabetes.
A university degree was held by 12 of the 136 (9%) and a university of applied sciences degree by 45 (33%). Such higher education appeared to have been received somewhat more often by the subjects of the non-PDR group than those with PDR, but the difference is not statistically significant (p=0.131). Of the 136 participants, 61 (45%) had finished vocational school. Seven subjects (5%, six men and one woman) had no secondary education after comprehensive school; six of these were diagnosed with PDR (Table II). Ten participants (7%) were full-time students.
Highest education received and the stage of diabetic retinopathy.
Five of these subjects doing further studies as full-time students.
Two of these subjects doing further studies as full-time students.
Two of these subjects doing further studies as full-time students.
One of these subjects doing further studies as full-time student.
Non-PDR= non-proliferative diabetic retinopathy, PDR= proliferative diabetic retinopathy.
A full-time job was held by 63 of the 92 subjects (68%) and 25 of 42 (60%) in the non-PDR and the PDR group, respectively. Four (4%) vs. six (14%) subjects were unemployed, and none vs. five (12%) were on a full-time pension. One patient with PDR was on a partial pension. The rest of the subjects were studying, working part-time or on maternity leave. Patients with PDR were more likely to be unemployed or on a pension (p<0.001) than those with no or less severe DR (Table III). The unemployment rate did not differ by gender.
Employment of study subjects in relation to proliferative diabetic retinopathy status in 2007.
Includes a subject on partial pension.
Non-PDR= non-proliferative diabetic retinopathy, PDR= proliferative diabetic retinopathy.
Three women and one man of the study cohort were visually impaired due to DR with best-corrected visual acuity (BCVA) <0.3 Snellen. One of them was totally blind. All four visually impaired subjects were on full or partial pension. At the time of the evaluation the only blind patient was on maternity leave. Of the six pensioners of the cohort, the remaining two also had a reduced BCVA, but to a lesser extent. None of the unemployed subjects, or those with only a comprehensive school education, had low vision.
The difference in age of onset of T1D with differing employment status, educational level, marital status, or number of children was not statistically significant.
Discussion
In the current study, a third of the young adults with childhood-onset T1D had PDR with related visual problems, and possible co-existing diabetic complications. PDR appeared to be associated with low levels of education, and had a negative impact on employment. PDR did not, however, seem to affect marital status or the number of children.
A third of the subjects had developed PDR by early adulthood despite available modern diabetes care including screening programs for DR. Provided that PDR is detected early enough, the fundi showing neovascularization may in most cases be treated successfully in terms of preserving visual function. The current first-line treatment is panretinal laser photocoagulation. Though sight-saving for thousands of patients with diabetes during the past 30 years, laser treatment does have side effects. These include impaired sensitivity of the visual field and night vision [22]. Any treatment-induced impairment in visual performance is, however, usually subjectively minor. In some cases, PDR still results in low vision or blindness. In primary health care, detection of advancing retinopathy and correctly timed referral to treatment are invaluable in the chain preventing loss of vision. Delayed onset of treatment as well as exceptionally aggressively progressing DR present challenges which are hard to overcome [23].
PDR causes decreased vision, and in this study PDR was associated with an increased chance of having received no education after compulsory comprehensive school, being unemployed, or on a pension. There is also a trend towards a lower educational level for the subjects with PDR having received education, than those in the non-PDR group. Lower education level and higher unemployment rate or being on pension are likely to result in lower income. Whether this is true for these patients is unclear as the subjects were not asked about their annual income.
T1D may markedly reduce school attendance [24] and thereby negatively influence an individual’s academic performance and future opportunities. A Finnish study reported that patients with T1D drop out of high school, and vocational and commercial schools more often than controls [25]. Delayed social maturation was described with difficulties developing independence from parents, in sexual maturation and to some extent in education and employment [25]. Other studies have also found that childhood-onset T1D has possible repercussions for career development and adult employment [14,26]. In this study, 12% of the subjects with diabetes were unemployed or on a pension, while 8% of the 30-year-old population (N=67,516) in Finland concurrently were unemployed (N=3977) or on a pension (N=1215); 86% of the general population aged 30–34 years had completed upper secondary school or vocational school [27]. In comparison, the study subjects fared better with only seven of 136 (5%) not having completed similar education. In a Swedish study, a substantial disparity in the advantage of a non-diabetic control group was found when comparing the frequency of successful employment between a group of young adults with T1D and controls, both lacking upper secondary education [14].
The trend in onset of childhood diabetes towards younger age is a challenge [1–3]. Encouragingly, the subjects of the current cohort with onset of diabetes before 5 years of age were not more likely to have PDR or to be less better off in any respect than those with later-onset T1D.
In a population-based Finnish cohort of those born between 1948 and 1979 both men and women with childhood-onset T1D were observed to have lower fertility than non-diabetic individuals [28]. In addition, a recent German study found that men and women with T1D have fewer children and are more often childless than the age-matched reference population [29]. However, the difference in fertility between controls and women with T1D has become less obvious in more recent birth cohorts. This change results from avoiding subfertility by better metabolic control [30], along with improved pregnancy outcomes generally, and more approving attitudes towards diabetic pregnancies by both health care personnel and diabetic patients [28].
In this study, both genders were equally likely to be parents and at least as likely to have a family and children as the general population. Women with T1D are advised to have children earlier rather than later. If the subjects are able to follow this advice, it may result in having more children in the early fertile years than the general population. During the later fertile years the general population may then catch up and surpass in terms of the number of children, but it is not known yet as the subjects of the study are still of child-bearing age. The diagnosis of PDR did not affect the number of children the subjects had. This may reflect relatively good overall health even in the subjects with PDR, and the patients not being advised against pregnancy. Possible voluntary childlessness was not addressed in the questionnaire. In addition, marriage or co-habitation was at least equally common among the subjects of the study as the general population.
Limitations of the current cross-sectional study include the small number of subjects, and that a third of the subjects of the population-based cohort did not participate. There is, however, no reason to believe that the actual social well-being of young adults with T1D in Finland would not be as good as the study indicates.
Conclusions
The majority of this population-based cohort of young adults with childhood-onset diabetes live an active life similar to the general population of their age in Finland. On average, the subjects had received education, were employed, had families, and were raising children. PDR appeared to be associated with lower levels of education and a higher risk of unemployment.
Footnotes
Conflict of interest
None declared.
Funding
This work was supported by Silmäsäätiö; Evald and Hilda Nissi Foundation; Sokeain Ystävät ry and Duodecim.