Do high CGM readings at age 60 increase the risk of diabetes?

Question

Hello doctor,

I am considered a “normal” body weight, but I have gained 15 pounds over the past seven years, with too much body fat and not enough muscle, confirmed by a DEXA scan. I have tried everything to lose the fat. I eat healthy, watch my calories, exercise regularly, and stay active seven days a week. Something feels wrong.

I decided to try a continuous glucose monitor (CGM). My father had type 2 diabetes. I have what is now considered PCOS and had borderline gestational diabetes. I am 60 years old and postmenopausal. My A1C and all other laboratory markers are normal.

However, the CGM shows that my blood sugar is all over the place, with frequent ups and downs. It is not steady at all, often over 200 and sometimes as high as 250. It is almost always over 140 after eating, even though I eat healthy meals. Finger-stick testing confirms these readings.

My primary care doctor told me to stop using the CGM because my A1C and blood work are normal. My concern is that, given these CGM readings, I may develop diabetes in the future. Is this possible?

If you saw a patient with this scenario, what would you tell them? What is your advice? Are these CGM readings telling me something important? Is there something I can do now to prevent diabetes?

Please help.

Thank you.

Answer 1

Hello,

Welcome to icliniq.com.

I understand your concern.

What you are describing is actually a situation that is being seen more often with CGM (continuous glucose monitoring) use in people who do not have diabetes, and it does not mean that something must be seriously wrong. A normal A1C (glycated hemoglobin) with normal fasting glucose and an excellent lipid profile strongly argues against current diabetes or even established prediabetes. CGMs measure interstitial glucose, which can exaggerate short-term peaks, especially after meals, exercise, stress, poor sleep, or hormonal changes, and postmenopausal insulin resistance can amplify these swings even in metabolically healthy people. Brief post-meal spikes above 140 or even transiently above 200 can occur in some individuals without progressing to diabetes, particularly when the glucose comes back down efficiently, which your normal A1C suggests it does. What matters most for future diabetes risk is the overall glucose exposure over time, not isolated peaks, and A1C plus fasting glucose remain the best validated markers for that risk. That said, your history of PCOS (polycystic ovary syndrome), gestational diabetes, and family history does mean you have a higher lifetime risk, so your concern is reasonable.

If I saw a patient like you, I would reassure you that you do not have diabetes now, but I would suggest a structured approach rather than ignoring it, such as a formal oral glucose tolerance test with insulin levels to assess insulin resistance, reviewing meal composition rather than calories alone, prioritizing resistance training to rebuild muscle mass, ensuring adequate protein intake, optimizing sleep and stress, and repeating A1C periodically.

The CGM numbers are not meaningless, but they are not diagnostic on their own and should not override normal standard tests. Think of them as a signal to refine lifestyle and monitor intelligently, not as a prediction that diabetes is inevitable.

I hope this answers your questions.

Thank you.