The amount of sunlight a person is exposed to can affect their risk of diabetes. If you already have diabetes, it can affect your management of the condition. Daylight saving time (DST) can also affect your blood sugar, especially if you inject insulin or use an insulin pump. Read on to learn more about the impact of sunlight and time changes on blood sugar levels.
Does sunlight affect blood sugar levels?
Summer can be a tricky time for diabetes management. Exposure to the sun for long periods – whether you’re active or idle – can cause hyperglycemia (high blood sugar) due to dehydration. This is because less blood flows through your kidneys so they can’t work as efficiently to clear excess blood sugar from your urine.
Sustained exposure to high temperatures can also cause blood vessels to expand. For people who take insulin to manage their diabetes, this increases the rate at which the body absorbs insulin and can potentially lead to hypoglycemia (low blood sugar).
Still, some research has shown that exposure to sunlight can help regulate blood sugar and reduce the risk of cardiovascular disease in people who do not have diabetes. In people with diabetes one study showed that people who had prolonged exposure to sunlight had improved blood sugar control, compared to those who did not. It’s important to note that these studies were very small in size, so larger, more comprehensive studies are needed to confirm these results.
Does daylight saving time affect diabetes management?
DST is done in most Canadian provinces and territories, where clocks are adjusted forward in the spring and then backward in the fall to make better use of daylight. The time changes as part of DST can disrupt sleep patterns, potentially affecting your blood sugar levels and overall diabetes management.
The first few weeks after the start of DST change can be particularly challenging. Losing an hour in the spring can make you feel a little drowsy over the next few days, not to mention that your blood sugar levels may be affected.
When returning to standard time in the autumn, gaining an extra hour of sleep sounds great but the time change can still affect people with diabetes. The shift might lead to changes in insulin requirements and the timing of injections, as well as fluctuations in blood sugar levels. You may sleep more, but there is also a potential adjustment period for diabetes management.
Some diabetes advocates around the world – including Canada – have called for an end to DST due to the increased risk of complications for people with diabetes (such as severe hypoglycemia) and other chronic diseases. At this time, no government has opted to enact such legislation.
Time changes and managing diabetes devices
People with diabetes should ensure that the time and date are set correctly on diabetes devices, including insulin pumps, blood glucose meters and continuous glucose monitoring systems. (While some devices adjust automatically to DST and back to standard time, many others do not.) This is necessary to ensure that blood sugar readings are accurate and the correct insulin dose is delivered at the right time.
Tips for managing daylight saving time
Follow these tips to help you manage your blood sugar during DST:
- Adjust devices: ensure that your insulin pump, blood glucose meter and CGM system all reflect the correct time. Most device manufacturers’ websites offer step-by-step instructions regarding how to change the time on your device.
- Maintain normal routines: when your daily rhythms are altered, it can lead to a variety of physical and mental health issues. Stick to your usual daily routine as closely as possible, including meal times, exercise regimens and sleep schedules.
- Check blood sugar levels: keep a close eye on your blood sugar levels during the transition period and be prepared to make necessary adjustments to your diabetes medication or insulin dosages in consultation with your diabetes healthcare team.
- Prioritize sleep: pay extra attention to your sleep schedule and try to get adequate rest during the time change adjustment period.
- Stay connected: contact your diabetes healthcare team if you experience persistent disruptions in your diabetes management or sleep patterns.
What is the role of vitamin D?
Vitamin D from exposure to natural sunlight may play a role in the prevention of diabetes. Researchers have noted that a person’s vitamin D status can affect how well their body utilizes insulin: adequate levels of vitamin D may enhance the body’s response to insulin, resulting in lower blood sugar levels, while inadequate levels of vitamin D may make the body less sensitive to insulin.
It is important to note that, at this time, the Diabetes Canada guidelines do not recommend the use of vitamin D supplements for the management of diabetes.
Sunlight may have a positive effect on your overall diabetes management, particularly blood sugar control. However, it is important to note that prolonged exposure to sunlight, high temperatures and time changes, particularly during DST, can have a negative effect. Plan ahead to manage the time of year when the clocks change. And speak with your diabetes healthcare team about your exposure to sunlight and how it may affect your diabetes management.
