Self-monitoring of blood glucose (SMBG) is an important component of the overall treatment of diabetes. The use of SMBG in patients with type 1 diabetes and type 2 diabetes requiring insulin therapy is now relatively well established, whereas the routine use of SMBG in non-insulin treated type 2 diabetes is controversial, especially with regard to the frequency and role of monitoring is inconclusive. Most of the available observational and controlled studies suggest that SMBG helps control glycemia and complications in this group of patients, but some studies suggest that SMBG increases patient psychological stress and no benefit is seen. In this paper, we focus on the main role of SMBG in non-insulin treated type 2 diabetes patients, the possible negative effects and how to determine the timing and frequency of monitoring based on the available data. I. Positive effects of SMBG in non-insulin-treated patients with type 2 diabetes. The Kaiser Permanente cohort study showed a 0.6% reduction in HbA1c in the SMBG group and a 0.2% increase in HbA1c in the non-insulin-treated type 2 diabetic patients; a meta-analysis by Poolsup et al. found that SMBG was effective in reducing HbA1c levels due to patients further refining their glucose-lowering regimen based on SMBG; DOVEs study evaluated the effect of intensive glucose monitoring on glycemic control in patients with type 2 diabetes, and the results suggested that SMBG has an important role in glycemic control; a meta-analysis of SMBG in non-insulin-treated patients with type 2 diabetes showed that SMBG reduced HbA1c levels, which was statistically significant; a recent meta-analysis reported that HbA1C levels in the SMBG group at six months were Another clinical trial of SMBG in this group of patients showed that SMBG was effective in reducing HbA1c levels by 0.24% (p<0.00001) and significantly improved blood glucose levels in the HbA1c>8% group, while the reduction in the HbA1c<8% group was not significant. The overall results of the above study showed that SMBG in non-insulin treated type 2 diabetic patients (especially those with HbA1c>8%) can reduce HbA1c levels, bring their blood glucose under control, and reduce the occurrence of complications. In addition, SMBG has been shown to reduce or delay the development and progression of diabetic microangiopathy as well as diabetic macroangiopathy: the ROSSO study, a retrospective, controlled, epidemiological cohort of 3,268 patients with type 2 diabetes, found a 51% reduction in the risk of fatal endpoint events in the SMBG group compared to the non-SMBG group and a 32% reduction in the risk of non-fatal endpoint events. The long-term benefits of SMBG in the entire type 2 diabetes population were demonstrated for the first time. Epidemiological studies and COX risk-proportional models in cohort studies corrected for confounders found not only a reduction in diabetes-related and all-cause mortality, but also a 79% reduction in cardiovascular mortality, a 55% reduction in the risk of cardiac death, and a reduced risk of retinopathy in the SMBG and non-SMBG groups of patients treated with diet and oral hypoglycemic agents. SMBG facilitates patient self-regulation and adjustment of treatment regimens and medication doses, helps physicians to adjust treatment regimens and assess patients’ risk of complications, and facilitates communication between physicians and patients. All of these suggest the positive role of SMBG in non-insulin treated type 2 diabetes patients. 1. SMBG may have a negative impact on quality of life and patient self-satisfaction. Unexplained changes in blood glucose may cause distress to patients, and repeated unsatisfactory blood glucose may lead to frustration and self-blame, and some may even abandon the treatment plan. Franciosi et al. reported higher HbA1C levels and greater psychological burden in the SMBG group in these patients. Analysis of the reasons may be due to the fact that most patients did not adjust their treatment plan according to their blood glucose and blindly developed fear and psychological burden, thus affecting the quality of life. 2. SMBG may bring certain financial burden to patients The price of blood glucose meter and test strips required for SMBG is higher, and in some countries (such as China), this related cost is in the category of self-payment, which causes certain psychological burden and resistance to patients. The American College of Endocrinologists/American Association of Endocrinologists believes that diabetes is a disease that requires self-management and SMBG is essential in diabetes management; the American Association of Diabetes Educators recommends that all health care workers should encourage SMBG in patients with diabetes, regardless of whether they are receiving Insulin, oral medications or a combination of both; the ADA states that SMBG is necessary for all patients, but that the frequency of SMBG monitoring varies by treatment method. The frequency or timing of glucose monitoring is currently controversial, and the IDF recommendations for the timing and frequency of glucose monitoring are as follows. SMBG protocols should be individualized according to each patient’s specific education, habits, clinical needs and physicians’ needs for glucose data, and the cost of SMBG should be weighed. The timing of blood glucose monitoring is usually fasting, before and 2 hours after meals, at bedtime and between 2 and 3 am. Blood glucose monitoring before bedtime and in the morning on an empty stomach can be used to detect and assess fasting hyperglycemia, while monitoring before lunch and dinner and at night can reflect asymptomatic hypoglycemia, and monitoring after meals can detect postprandial hyperglycemia. For patients with type 2 diabetes mellitus who are newly diagnosed with diabetes mellitus, recent large fluctuations in blood glucose, unstable blood glucose control, recent occurrence of hypoglycemia, medication change or dose adjustment, pregnancy, surgery, exercise, going out, alcohol consumption and other non-insulin therapy, the patient’s blood glucose profile should be systematically evaluated in order to understand the pattern of blood glucose fluctuations. The “Intensive SMBG” program is commonly used, and there is the “7/5-point method”, which means that the blood glucose before and after three meals (the “5-point method”: fasting, after breakfast, after lunch, before and after dinner) is tested every day for one to three days. The blood sugar can also be tested by the “crossover method”, i.e., the blood sugar can be tested at different times every day for a week, such as before and after breakfast on the first day, before and after lunch on the second day, before and after dinner on the third day, and so on. In case of hypoglycemia, attention should also be paid to monitoring premeal blood glucose and night blood glucose. Patients with diabetes other than those mentioned above can also undergo the “intensive SMBG program”, which means that they can regularly take 7 time points of blood glucose on one day to understand the blood glucose profile. After the blood glucose profile is fully understood, the frequency and intensity of SMBG should be reconsidered for those with stable disease. In non-insulin-treated type 2 diabetes patients, blood glucose fluctuations are generally small. If patients have more than half of their blood glucose test results fall within the target range or are unable or unwilling to monitor blood glucose multiple times a day for financial reasons or other problems SMBG can be appropriately reduced under the guidance of the healthcare provider. Usually, it can be reduced to two to three times a week for pre- and postprandial glucose testing; if the glucose control is good and stable, the SMBG cycle can be further extended. The most common practice is to perform three tests per day – fasting and pre/postprandial glucose at the largest meal (usually dinner) (twice a week, one day Monday through Friday and one day on the weekend), which has been used with good results in early diabetes education programs. Fasting blood glucose captures blood glucose trends, and pre/post meal (maximum meal) blood glucose is monitored mid-week and on weekends, followed by changes in diet and exercise to achieve optimal results. After that, change to monitor the other meal pre/post meal blood glucose and bring it to the standard. In contrast, bedtime and morning fasting SMBG can be used to detect and assess fasting hyperglycemia, and pre-lunch and pre-dinner SMBG can be used to detect asymptomatic hypoglycemia. The frequency of monitoring should be increased for those with large blood glucose fluctuations, and blood glucose needs to be monitored once or twice a day. In special cases, such as recent hypoglycemia, we should pay attention to monitoring blood glucose before meals and at night before and after exercise, after drinking alcohol or before driving out, and if necessary, we should monitor blood glucose 4 to 6 times at different times of the day to understand the change pattern of blood glucose in 24 hours a day. At present, the status quo of blood glucose monitoring in China is still not optimistic, although the awareness has been greatly improved, the quantity is still only one tenth of that in Hong Kong and one percent of that in the United States. The results of Dai Xia et al.’s survey on self-monitoring of blood glucose in diabetic patients showed that the frequency of monitoring was low, accounting for only 16.67% of patients once a day and 33.33% of patients were not monitored reasonably and regularly. Improving the level of awareness of SMBG among medical practitioners is one of the important ways to solve the weakness of current diabetes monitoring management; in addition, it is suggested that the national health administration should increase the investment to reduce the economic burden of patient monitoring.