Key messages
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Based on three included studies, we found that checking more often might help people keep their blood sugar under better control over time, although the evidence is very uncertain.
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Future studies are needed looking at the best way for people with type 1 diabetes to check their blood sugar at home, including how often to check, when to check, and what target numbers to aim for, so they and their doctors have clear guidance.
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People wanting to know how often to check their blood sugar should talk to their healthcare provider, as the best choice may depend on the patient's specific needs.
What is type 1 diabetes?
Type 1 diabetes is a lifelong condition that occurs when the body can no longer make insulin. Insulin is a hormone that turns food into energy and manages the level of sugar in your blood. People with type 1 diabetes need to take insulin every day. Many also check their blood sugar regularly, which can help them decide on insulin doses and manage food, exercise, and daily activities more safely. People with type 1 diabetes typically check their blood sugar 4 to 10 times a day.
Guidelines offer different advice about how to check blood sugar. It remains unclear which approach works best, especially where test supplies or other resources are limited.
What did we want to find out?
We wanted to find out what kind of blood sugar checking works best for adults with type 1 diabetes in everyday life. This includes how many times a day people may need to check their blood sugar, what times of day checking is most useful, and what blood sugar range they should try to stay within. We also wanted to know whether different ways of checking blood sugar affect people’s health and daily well-being.
What did we do?
We looked for studies that compared different ways of checking blood sugar in adults aged 18 years and older with type 1 diabetes. This included how often people checked their blood sugar, what times of day they checked it, and the blood sugar levels they were trying to reach. We compared and summarised the results of the studies and rated our confidence in the evidence based on factors such as study methods and sizes.
What did we find?
We found three studies involving 16,481 adults with type 1 diabetes. All three studies only looked at how often people checked their blood sugar. No studies provided evidence about the best times of day to check blood sugar or the best blood sugar targets to use.
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In one study (123 people), people who checked their blood sugar more carefully throughout the day may have had slightly lower blood sugar levels after nine months than those receiving usual care according to standard diabetes guidelines, but the evidence is very uncertain.
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In the other two studies (16,358 people), which followed people for up to two years, those who checked their blood sugar more often tended to have better blood sugar control. Those who checked most often had the lowest blood sugar levels. However, this evidence is very uncertain.
The studies we found all pointed in the same direction, suggesting a benefit with more frequent checking.
No study reported effects on:
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low blood sugar events;
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diabetic ketoacidosis, a life-threatening complication of diabetes that can occur when there is a lack of insulin;
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long-term diabetes complications; or
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quality of life
People who are considering how often to check their blood sugar should discuss this with their healthcare provider, as the best choice may depend on individual circumstances.
What are the limitations of the evidence?
We have very low confidence in the evidence. The studies were few, small, or had problems with their methods. Because of this, we still do not know how often adults with type 1 diabetes should check their blood sugar, the best times of day to check it, or what blood sugar levels they should aim for.
How up to date is this evidence?
The evidence is current to January 2026.
مطالعه چکیده کامل
اهداف
To assess the effects of different timing, frequency, and glycaemic target values for self-monitoring of blood glucose (SMBG) in adults with type 1 diabetes mellitus.
روشهای جستوجو
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Science Citation Index Expanded and Emerging Sources Citation Index (Web of Science), ClinicalTrials.gov, and the WHO ICTRP, without language restrictions. The date of the last search across all databases was 7 January 2026.
نتیجهگیریهای نویسندگان
No studies evaluated different timings of self-monitoring or different glycaemic target values. Three studies (one randomised controlled trial and two observational studies) assessed the frequency of self-monitoring and haemoglobin A1c. More frequent self-monitoring may be associated with lower haemoglobin A1c, although the evidence is sparse, frequency categories were inconsistent across studies, and the included studies had methodological limitations. The certainty of the evidence was very low for all outcomes, driven by risk of bias, imprecision, and inconsistency across studies. No studies reported hypoglycaemia, diabetic ketoacidosis, quality of life, or other critical outcomes. The evidence is insufficient to draw any firm conclusions about the effects of different self-monitoring strategies in adults with type 1 diabetes mellitus.
حمایت مالی
This review was funded by the World Health Organization through an Agreement for Performance of Work (APW 203512799).
ثبت
The review was registered in PROSPERO (CRD42025639736) in February 2025.
