Glucose monitor meant to monitor low blood sugar

DEAR DR. ROACH: I am a 71-year-old Type 2 diabetic woman, but I find the glucose monitoring systems requiring blood samples so painful to use that I don’t test. At present, I get along by taking a 500-milligram metformin tablet three times a day and having bloodwork done about twice a year. My last fasting glucose test result (1/19/18) was 134 mg/dL, and my HbA1c was 6.9 per cent. Should I consider a continuous glucose monitor? I am overweight, so that is a factor I am working on. — C.P.

ANSWER: A continuous glucose monitor checks and electronically records many blood sugar readings, as often as every five minutes, which can sometimes be read by the user in real time or can be downloaded by the clinician at the end of two weeks (at which point, another unit is placed). The units themselves look like large buttons and contain a very thin needle with a sensor that measures the blood sugar.

CGM systems are used most often in people with Type 1 diabetes, but some patients with Type 2 may be candidates for the system, particularly those whose blood sugars are known or suspected to go too low.

I spoke with an expert at my institution, Esther Wei, nurse practitioner and certified diabetes instructor, who would not recommend CGM for you, as it is unlikely that you would have low blood sugars being on metformin. Most insurances also require that their members be on both longacting and short-acting insulin for them to cover CGM.

Your blood sugar levels are excellent, and your A1c levels are near the optimum advised in the most recent guidelines. Losing weight may improve several areas of health, but from the standpoint of diabetes, I wouldn’t increase your monitoring if it is so painful for you.

DEAR DR. ROACH: During the past year or two, I have been using a daily sublingual vitamin B-12 supplement sort of as witchcraft to treat minor numbness in my feet, recognizing in the absence of signs, symptoms or laboratory evidence of deficiency that taking it has no science.

Today I opened a fresh bottle of tablets and found that the tablet no longer dissolved under my tongue and actually was nondissolvable and hard (the previous tablet had been chalky and dissolvable). The small print on the new label said to swallow with food once daily, whereas the small print on the former bottle said to dissolve under the tongue three times daily. The dosage also had changed from 500 to 1,000. — Dr. L.D.B.

ANSWER: Even the most educated people may still benefit from the placebo response, which is the likely case for you, in absence of known B-12 deficiency. B-12 is safe and relatively inexpensive.

In people with known B-12 deficiency, sublingual (under the tongue) preparations and swallowed tablets were equally effective at returning blood B-12 levels to normal. The study looked at vegans, who do not get B-12 in the diet, as well as people with pernicious anemia, who are unable to absorb B-12 efficiently due to an autoimmune disease that prevents the body from making a protein called intrinsic factor. Intrinsic factor improves B-12 absorption greatly, but with enough B-12 (1,000 mcg once a day or 500 mcg three times a day are more than enough), the body can absorb as much B-12 as it needs. You can take either preparation.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or request an order form of available health newsletters at 628 Virginia Dr., Orlando, Fla., 32803. Health newsletters may be ordered from www.rbmamall.com.