DEAR DR. ROACH: I am a 75-year-old man with an elevated A1C level; I was diagnosed with prediabetes. I feel healthy but have struggled to lose weight. I was wondering what your feeling are on using a glucose monitor. — F.M.

ANSWER: A continuous glucose monitor is a device shaped like a disc, and the smallest of them are only just larger than a quarter. They measure blood sugar levels without having to prick the finger at intervals of 1-15 minutes and send the result instantly to a meter or a smartphone. A single device can usually stay in place for a week to 15 days, and a person can do all their activities, including bathing and showering, with them. I see them all the time now.

Although insurance generally pays for continuous glucose monitors in those with Type 1 diabetes or those with Type 2 diabetes who have low blood sugar, people can now buy these devices without a prescription.

In a person with prediabetes, there are some advantages. You can see how your meals raise your blood sugar, giving you immediate feedback on which foods or combinations raise your blood sugar quickly — and which ones do not. You can also see how exercise can affect your blood sugar, especially after eating.

This can help you make better diet choices to prevent or at least slow the progression to overt diabetes. I don’t think people need to wear them all the time; using one once or occasionally can give the feedback needed to choose wisely.

As far as weight loss goes, I don’t think a glucose monitor is particularly helpful, as blood sugar levels aren’t a good guide to effective weight loss. Working with a registered nutritionist or a diabetes educator is much more likely to give you helpful information.

For those in whom pharmacological treatment is considered, metformin is a time-honored treatment that helps prevent diabetes and promotes weight loss. The new GLP-1 drugs like tirzepatide (Zepbound) or semaglutide (Wegovy) are even more effective at preventing diabetes and promoting weight loss. But in my opinion, they need to be used judiciously and only after a thorough discussion of the risks and benefits — particularly the weight regain that happens in most people when they stop the medication.

DEAR DR. ROACH: I’m on losartan for my blood pressure. I’ve noticed my hair becoming extremely thin. Could losartan be the cause? Any suggested remedies? — K.K.

ANSWER: I did not find reports of hair loss due to losartan, which is a common blood pressure medicine. It was not listed in the manufacturer’s list of side effects, but it is still possible this is a rare reaction that just hasn’t been reported.

However, at about the time that many people have high blood pressure is about the time their hair starts to thin. The most common cause of thinning hair in women is female pattern hair loss. Your regular doctor can make this diagnosis, but a dermatologist is the real expert in hair conditions.

If you do have female pattern hair loss, topical minoxidil and oral spironolactone are the first-line treatments, but it is good to be sure of the diagnosis as there are other possibilities.