DM: Physical Activity (2007)

Study Design:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
To examine the amount and patterns of physical activity and energy intake in adolescent females with Type 1 diabetes in comparison with healthy age-matched controls.
Inclusion Criteria:
All girls aged 12 - 19 at the pediatric department who had type 1 diabetes for more than 2 years were asked to participate.
Exclusion Criteria:
Excluded due to severe concurrent diseases (mental retardation or rheumatoid arthritis).
Description of Study Protocol:


Patients in pediatric department.  Controls selected from register of county taxation authorities.


Prospective Cohort Study.

Blinding used (if applicable)

Not applicable.

Intervention (if applicable)

Not applicable - physical activity and energy intake measured over 7 days.

Statistical Analysis

Power calculation:  35 diabetic girls and 70 controls would be needed to detect differences.  ANCOVA with study group as fixed factor and age as covariate was used to examine differences in physical activity variables, energy intake and clinical characteristics between groups.  Between-group mean difference for total physical activity was calculated with ANCOVA adjusted for age.  When data distribution was skewed, we used median and interquartile range to describe the data and Mann-Whitney U tests to compare the groups.  Linear regression analyses used to assess the relations of physical activity and energy intake to metabolic control and body composition in each study group.

Data Collection Summary:

Timing of Measurements

Physical activity and energy intake assessed over 7 days.

Dependent Variables

  • Height, weight, BMI
  • HbA1c measured through HPLC

Independent Variables

  • Physical activity measured with uniaxial accelerometer
  • Energy intake assessed with 7-day food diary

Control Variables

  • Pubertal stage
  • Age
Description of Actual Data Sample:

Initial N:  43 girls eligible; 4 excluded due to exclusion criteria.  Of the remaining 39 girls, 26 (67%) agreed to participate.  52 control girls. 

Attrition (final N):  26 girls with type 1 diabetes, 49 control girls.  The subjects who refused to participate did not differ from the study population in age, BMI, insulin dosage or HbA1c.

Age:  Mean age diabetic girls:  15.7 +/- 2.1 years, mean age controls:  15.8 +/- 2.1 years 

Ethnicity:  not mentioned

Other relevant demographics:

Anthropometrics:  2 controls matched for age, sex and residential area were selected for each patient.

Location:  Sweden


Summary of Results:


Dietary Intake

Diabetic Girls


Total energy intake (MJ/day) 8.5 +/- 1.8 8.4 +/- 2.6 NS
% of predicted TEE

84 +/- 18

86 +/- 28


Fat (%)

34 +/- 6

33 +/- 4


Protein (%) 16 +/- 2 14 +/- 3 0.0003
Carbohydrate (%) 50 +/- 6 53 +/- 4 0.02
Fiber intake (g/day) 20 +/- 7 16 +/- 6 0.01

Other Findings

No significant differences between groups in height, weight, BMI or waist circumference.

There was a tendency towards lower total amount of physical activity in the diabetes group but the difference between the study groups did not reach statistical significance (464 +/- 123 counts/min/day for diabetics; 523 +/- 138 counts/min/day for controls, P = 0.06).

No difference was found between groups regarding total energy intake (8.5 +/- 1.8 MJ/day for diabetics; 8.4 +/- 2.6 MJ/day for controls).

The carbohydrate intake was lower (P = 0.02) and the protein (P = 0.0003) and fiber (P = 0.01) intakes were higher in girls with diabetes.

No association was observed between physical activity, energy intake and HbA1c. 

Author Conclusion:

To conclude, in this prospective cohort study we found a tendency towards lower physical activity but no differences in energy intake between girls with type 1 diabetes and age-matched controls.  Larger studies are needed to further explore the importance of the amount of physical activity for excessive weight gain in adolescent girls with type 1 diabetes.

Funding Source:
Reviewer Comments:
2 matched controls per patient.  Authors note that physical activity may have been influenced by season.  Number of subjects did not meet estimates from power calculations.
Quality Criteria Checklist: Primary Research
Relevance Questions
  1. Would implementing the studied intervention or procedure (if found successful) result in improved outcomes for the patients/clients/population group? (Not Applicable for some epidemiological studies) N/A
  2. Did the authors study an outcome (dependent variable) or topic that the patients/clients/population group would care about? Yes
  3. Is the focus of the intervention or procedure (independent variable) or topic of study a common issue of concern to dieteticspractice? Yes
  4. Is the intervention or procedure feasible? (NA for some epidemiological studies) N/A
Validity Questions
1. Was the research question clearly stated? Yes
  1.1. Was (were) the specific intervention(s) or procedure(s) [independent variable(s)] identified? Yes
  1.2. Was (were) the outcome(s) [dependent variable(s)] clearly indicated? Yes
  1.3. Were the target population and setting specified? Yes
2. Was the selection of study subjects/patients free from bias? Yes
  2.1. Were inclusion/exclusion criteria specified (e.g., risk, point in disease progression, diagnostic or prognosis criteria), and with sufficient detail and without omitting criteria critical to the study? Yes
  2.2. Were criteria applied equally to all study groups? Yes
  2.3. Were health, demographics, and other characteristics of subjects described? Yes
  2.4. Were the subjects/patients a representative sample of the relevant population? Yes
3. Were study groups comparable? Yes
  3.1. Was the method of assigning subjects/patients to groups described and unbiased? (Method of randomization identified if RCT) Yes
  3.2. Were distribution of disease status, prognostic factors, and other factors (e.g., demographics) similar across study groups at baseline? Yes
  3.3. Were concurrent controls or comparisons used? (Concurrent preferred over historical control or comparison groups.) Yes
  3.4. If cohort study or cross-sectional study, were groups comparable on important confounding factors and/or were preexisting differences accounted for by using appropriate adjustments in statistical analysis? Yes
  3.5. If case control study, were potential confounding factors comparable for cases and controls? (If case series or trial with subjects serving as own control, this criterion is not applicable.) N/A
  3.6. If diagnostic test, was there an independent blind comparison with an appropriate reference standard (e.g., "gold standard")? N/A
4. Was method of handling withdrawals described? Yes
  4.1. Were follow-up methods described and the same for all groups? Yes
  4.2. Was the number, characteristics of withdrawals (i.e., dropouts, lost to follow up, attrition rate) and/or response rate (cross-sectional studies) described for each group? (Follow up goal for a strong study is 80%.) Yes
  4.3. Were all enrolled subjects/patients (in the original sample) accounted for? Yes
  4.4. Were reasons for withdrawals similar across groups? ???
  4.5. If diagnostic test, was decision to perform reference test not dependent on results of test under study? N/A
5. Was blinding used to prevent introduction of bias? Yes
  5.1. In intervention study, were subjects, clinicians/practitioners, and investigators blinded to treatment group, as appropriate? N/A
  5.2. Were data collectors blinded for outcomes assessment? (If outcome is measured using an objective test, such as a lab value, this criterion is assumed to be met.) N/A
  5.3. In cohort study or cross-sectional study, were measurements of outcomes and risk factors blinded? Yes
  5.4. In case control study, was case definition explicit and case ascertainment not influenced by exposure status? N/A
  5.5. In diagnostic study, were test results blinded to patient history and other test results? N/A
6. Were intervention/therapeutic regimens/exposure factor or procedure and any comparison(s) described in detail? Were interveningfactors described? Yes
  6.1. In RCT or other intervention trial, were protocols described for all regimens studied? Yes
  6.2. In observational study, were interventions, study settings, and clinicians/provider described? N/A
  6.3. Was the intensity and duration of the intervention or exposure factor sufficient to produce a meaningful effect? Yes
  6.4. Was the amount of exposure and, if relevant, subject/patient compliance measured? Yes
  6.5. Were co-interventions (e.g., ancillary treatments, other therapies) described? Yes
  6.6. Were extra or unplanned treatments described? Yes
  6.7. Was the information for 6.4, 6.5, and 6.6 assessed the same way for all groups? Yes
  6.8. In diagnostic study, were details of test administration and replication sufficient? N/A
7. Were outcomes clearly defined and the measurements valid and reliable? Yes
  7.1. Were primary and secondary endpoints described and relevant to the question? Yes
  7.2. Were nutrition measures appropriate to question and outcomes of concern? Yes
  7.3. Was the period of follow-up long enough for important outcome(s) to occur? Yes
  7.4. Were the observations and measurements based on standard, valid, and reliable data collection instruments/tests/procedures? Yes
  7.5. Was the measurement of effect at an appropriate level of precision? Yes
  7.6. Were other factors accounted for (measured) that could affect outcomes? Yes
  7.7. Were the measurements conducted consistently across groups? Yes
8. Was the statistical analysis appropriate for the study design and type of outcome indicators? Yes
  8.1. Were statistical analyses adequately described and the results reported appropriately? Yes
  8.2. Were correct statistical tests used and assumptions of test not violated? Yes
  8.3. Were statistics reported with levels of significance and/or confidence intervals? Yes
  8.4. Was "intent to treat" analysis of outcomes done (and as appropriate, was there an analysis of outcomes for those maximally exposed or a dose-response analysis)? N/A
  8.5. Were adequate adjustments made for effects of confounding factors that might have affected the outcomes (e.g., multivariate analyses)? Yes
  8.6. Was clinical significance as well as statistical significance reported? Yes
  8.7. If negative findings, was a power calculation reported to address type 2 error? Yes
9. Are conclusions supported by results with biases and limitations taken into consideration? Yes
  9.1. Is there a discussion of findings? Yes
  9.2. Are biases and study limitations identified and discussed? Yes
10. Is bias due to study's funding or sponsorship unlikely? Yes
  10.1. Were sources of funding and investigators' affiliations described? Yes
  10.2. Was the study free from apparent conflict of interest? Yes