Plain English Summary
Background and study aims
Type 1 Diabetes (T1D) is one of the most common chronic diseases of childhood, causing blood sugar levels to become too high. When children with T1D become teenagers or young adults, managing their diabetes is very important due to risky behaviours like unplanned pregnancies. Most young adults are not aware that there can be complications with both the mother and baby due to diabetes, such as birth malformations. Conception should be planned when the mother has normal blood sugar levels. It is important to provide education, counselling and contraception (methods to prevent pregnancy) in young women both with and without T1D. Contraception usually involves hormones (chemical messengers that control the bodies functions), such as birth control or an implantable medical device. Research is needed to examine what the metabolic effects (how food is processed to energy) of hormonal contraception in teenagers with T1D. Previous research has shown that hyperandrogenism (too much male sex hormones) and inflammation (swelling) are frequent problems in women with T1D. Another consideration in this study is to examine the impact of T1D and the use of contraceptives on telomere length. Telomere is the ending portion of the chromosome (part of the genes that carry out genetic information). Telomere length decreases with advancing age and is shortened in cases of type 2 diabetes. Recently, it was shown that the use of COC in adolescents with polycystic ovary syndrome (a syndrome that affects how a womens ovaries work causing irregular periods and other symptoms) decreases telomere length. Whether telomere length is affected by T1D in young women or by the use of contraceptives in these young women, is unknown. The aim of this study is to examine the impact of different types of contraception on young women with T1D when compared to young women without T1D.
Who can participate?
Young women aged 16 to 25 who have T1D and healthy women aged 16-25 years old.
What does the study involve?
Participants are provided counselling about contraception and pregnancy prevention. They are then offer either a contraceptive pill (taken by mouth) or the implantable rods as birth control methods. Participants are followed up for two years and provide blood samples before taking the contraception and at three, six, 12 and 24 months. The women with T1D and the women without are compared to see how the contraception impacts their metabolic control, bone mass, insulin sensitivity and telomere length.
What are the possible benefits and risks of participating?
Participants may benefit from receiving the contraceptive methods and medical control without cost for them. The only risk of the study is the already reported as well-known possible side effects of hormonal contraception.
Where is the study run from?
1. University of Chile (Chile)
2. Instituto Chilena de Medicina Reproductiva (ICMER) (Chile)
When is the study starting and how long is it expected to run for?
May 2017 to April 2021
Who is funding the study?
Who is the main contact?
Professor Ethel Codner
Prof Ethel Codner
Institute of Maternal and Child Research
Metabolic effect of the long-acting reversible contraceptive method (implant) compared to combined oral contraceptive in young women with type 1 diabetes
Adolescents/young women with T1D receiving hormonal combined oral contraception or a long-acting reversible method (implantable progesterone rod) exhibit a detrimental profile of markers associated with inflammation, insulin resistance, and telomere length compared with healthy non-diabetic young women receiving the same type of contraception. As wel, T1D young women will show lower bone mass than healthy young women.
IRB of the Servicio Salud Metropolitano Central (SSMC) of the Health Ministry of Chile, 29/05/2017, ref: N°431/2017
Interventional non randomised study
Primary study design
Secondary study design
Non randomised study
Patient information sheet
No participant information sheet available
Young women with type 1 diabetes or healthy controls.
Healthy participants and participants with T1D (N:40) seeking contraception are recruited. Counseling about contraception and pregnancy prevention is given to both groups of women.
Participants are offered either a combined oral contraceptive pill containing ethinyl estradiol 30 ug/desogestrel 0.15mg, or the implantable rod with etonogestrel, the active metabolite of desogestrel. Both methods are currently available for women of this age group and have been considered as first-line options for young women.
Participants are followed for two years and blood samples are obtained at baseline, three, six, 12, and 24 months.
Implanon (R) contraceptive implant and desogestrel/ethynil estradiol
Primary outcome measure
1. Inflammatory markers is measured using C-Reactive Protein Levels at baseline, three, six, and 12 months
2. Metabolic control (HbA1c) is measured using HbA1c with DCA-2000 (Siemens) equipment at month three, six, nine and 12
3. Bone Mass is measured using DXA (Lunar Prodigy GE) at baseline, 12 and 24 months
4. Insulin sensitivity is measured using estimated insulin sensitivity index, which includes the measurement of adiponectin and was validated for subjects with and without T1D6 at baseline, three, six, and 12 months
5. Telomere length is measured using blood tests at baseline and at 12 months
Secondary outcome measures
1. Metabolic control will be assessed at 18 and 24 months in women with type 1 diabetes
2. Bone mass DXA (Lunar Prodigy GE) and insulin sensitivity in all the participants is assessed using DXA (Lunar Prodigy GE) and insulin sensitivity index at 24 months of treatment
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Clinical diagnosis of T1D is clear (patient received treatment with insulin from the time of diagnosis with clinical evidence of severe insulin deficiency).
2. Age: 16-25 years old.
3. Seeking contraception.
4. HbA1c lower than 13%
5. Has not used hormonal contraception for the last three months
1. Age 16-25 years old
2. Seeking contraception
3. Has not used hormonal contraception for the last three months
Target number of participants
Based in this meta-analysis of effects of combined oral contraception on PCR levels, the required number of subjects needed to observe differences in is ten young women in each arm of the study. However, the continuation of the implant and combined oral contraception in adolescents after 24 months of use is 77% and 45%, respectively. Therefore, an initial sample size of twenty subjects in each arm is calculated to be sufficient to find differences in C-peptide levels throughout the study.
Participant exclusion criteria
Both groups of subjects (patients with type 1 diabetes and healthy controls):
1. Chronic conditions such as celiac sprue, epilepsy, cardiopulmonary or gastrointestinal conditions are present.
2. Use of steroidal medication.
3. Contraindications for using hormonal contraception (WHO criteria: migraine with aura, prothrombotic problems, etc)
Persons with type 1 diabetes:
1. HbA1c higher than 12.9%
2. Honeymoon period
3. Other type of diabetes
1. Menstrual cycle abnormalities according to the American Academy of Pediatrics.
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
University of Chile
Institute of Maternal and Child Research (IDIMI) Santa Roa 1234
Trial participating centre
Instituto Chilena de Medicina Reproductiva (ICMER)
José Victorino Lastarria 29 dp 101
University of Chile
Facility of Medicine (Facultad de Medicina)
Av. Independencia 1027
Fondo Nacional de Desarrollo Científico y Tecnológico
National Fund for Scientific and Technological Development, FONDECYT
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
planned presentation in meetings related to Diabetes and Endocrinology during 2020 and 2021. In addition, publication in a high-impact peer reviewed journal at the end of the study.
IPD sharing statement:
The datasets generated during and/or analysed during the current study are/will be available upon request from Ethel Codner at firstname.lastname@example.org
Intention to publish date
Participant level data
Available on request
Basic results (scientific)