Why is the home blood glucose meter inaccurate?

Expert: It is mainly used for auxiliary measurement and cannot replace professional testing

Intern journalist Chai Rong

Invasive home blood glucose meters that are simple to operate and small and portable are now popular. Non-invasive blood glucose meters, which are known as "no needles" and "no calibration", have also surged in sales in recent years. However, the reporter's investigation found that many invasive blood glucose meters and non-invasive blood glucose meters on the market are not small differences in measurement results compared with hospital examinations. Experts remind that home blood glucose meters are mainly used for auxiliary measurement and cannot replace professional testing.

Invasive blood glucose meter test strips are more expensive than machines

Mr. Liu, 82, who has diabetes, recently purchased an invasive home blood glucose meter, but the measurements surprised him. "After trying for a few days, I measured three times in a row within 10 minutes, and the results were different all three times, high and low." The anxious Mr. Liu took the blood glucose meter to the hospital for venous blood testing, and the hospital test results showed that the blood glucose value was 3.3 mmol/liter, and the blood glucose meter showed 6.5 millimoles per liter, a difference of 7.6 millimoles per liter.

The reporter investigated some pharmacies in the city and found that household blood glucose meters that collect fingertip blood are generally sold at a lower price, with prices ranging from 50 yuan to 200 yuan. But the price of test strips is not cheap, taking the best-selling brand of blood glucose meter as an example, the price of the blood glucose meter itself is 69 yuan, but it costs 1 yuan to buy its supporting box of 50 pieces of test strips. The staff of a pharmacy near Sihui told reporters that because the test strip is used in large quantities and consumed quickly, if the blood sugar is measured morning and night, 84 box of test strips can not be used for a month, and some elderly people are often reluctant to use test strips, and even ask whether the test strips can be used repeatedly.

In addition, the test strip size is small, generally about 5 cm in length and about 1 cm in width. Aunt Yuan, 92, has weak eyesight and suffered a stroke five years ago, and although she has recovered, she has suffered after-effects – always trembling when she takes things. "A small test strip, the old lady can't pick it up herself, it's easy to fall to the ground, not to mention accurately inserted into the hole of the blood glucose meter, we help her measure blood sugar." Aunt Yuan's daughter told reporters that many elderly people around them cannot independently complete the complex process of measuring blood sugar.

Non-invasive blood glucose meter accused of "flashy"

On an e-commerce platform, some merchants sell more than 5000,24 non-invasive blood glucose meters per month. These meters are small in size and can be worn on one arm to measure blood glucose in real time 400 hours a day within two weeks. The price of non-invasive blood glucose meters ranges from 3000 yuan to <>,<> yuan, which is much higher than the price of invasive blood glucose meters that take fingertip blood.

"From morning to night, the blood sugar is not accurate, the gap is too big", "The error is large, and the difference between the hospital measurement is about 2 millimoles per liter", "Only occasionally accurate, it is better to take fingertip blood"... The reporter noticed that many consumers reported on the Internet that the measurement data of the non-invasive blood glucose meter was quite different from that of the hospital, and some people even complained that the non-invasive blood glucose meter was an "IQ tax".

On the shelves of a pharmacy near Higashi-Shijo is a non-invasive blood glucose meter priced at 499 yuan. "If you use it yourself, an ordinary blood glucose meter is enough, and if you give it away, you can buy this non-invasive blood glucose meter." The staff revealed to reporters that the non-invasive blood glucose meter is not easy to sell, the price is higher is only one of the reasons, more importantly, many customers feedback that the non-invasive blood glucose meter is "flashy", and the measurement error is greater than that of the home blood glucose meter that takes fingertip blood.

Li Jing, deputy chief physician of the Department of Endocrinology of Beijing Chaoyang Hospital, introduced that the working principle of the non-invasive blood glucose meter is to use the sensor probe to make non-invasive measurements on the surface of the skin through fine vessel temperature, infrared, etc., which is inevitable to the local skin influence where the patient is placed the sensor device, such as the presence of subcutaneous tissue edema in the local skin, which may affect the accuracy of blood glucose measurement.

Home blood glucose meters also require an "annual check"

Meng Liuhuan, a general practitioner at the Xuexue Road Street Health Service Center in Haidian District, said that according to national regulations, the blood glucose measurement results of home blood glucose meters and hospital venous blood collection are allowed to have certain errors, as long as the difference between the results is within the range of 10% to 15%, it is acceptable. In addition to quality issues, many factors may also affect the accuracy of blood glucose measurement, for example, the wound cannot be squeezed hard or the fingertip can be pinched to take blood during blood collection, so as to avoid squeezing out interstitial fluid, which affects the accuracy of measurement.

"If the measurement results exceed the error range, it may also be that the test strip has been improperly stored or has exceeded the expiration date, which many people tend to overlook." Li Jing said that the test strip of the blood glucose meter needs to be stored in a relatively cool and dry environment without direct sunlight. The shelf life of the test strip is generally about 2 years, and the measurement should ensure that the test strip is within the validity period, otherwise the measurement results are unreliable. The test strip should also correspond to the brand and model of the blood glucose meter, otherwise it may also cause inaccurate or impossible measurement results.

In addition, the household blood glucose meter should be calibrated once a year, and consumers can call the relevant manufacturer's after-sales hotline according to the brand and model, obtain the quality control solution for self-calibration, or go to the blood glucose meter after-sales center for calibration.

Li Jing said that compared with the hospital's professional testing, the home blood glucose meter has its auxiliary use, which can help users monitor blood sugar in time under special circumstances such as hypoglycemic symptoms, missed doses and insulin, etc.; However, home blood glucose meters can only be used as a monitoring of the treatment effect, and cannot replace the test results of hospitals. (Source: Beijing Daily)