Substantial research has shown a high prevalence of type 2 diabetes mellitus among the elderly. Many of these patients have low quality of life, frequent complications, and poor health outcomes. However, little is known about the factors associated with quality of life in this patient population.
Social support, self-management behavior, and quality of life in elderly patients with type 2 diabetes mellitus
In this study, the total score of social support in elderly patients with type 2 diabetes mellitus was 43.40 ± 8.41; family support scored the highest (14.75 ± 2.99) in the three dimensions of perceived social support, indicating that the main source of support was the patient’s family. This finding was consistent with those of other studies [46]. Indeed, family plays a major role in patient care. Further analysis revealed that only 58.4–67.1% of patients received specific social support. Moreover, the proportion of patients who could not obtain sufficient support from family, friends, and others was 21.4%, 24.0%, and 25.4%, respectively. This means that community nurses and physicians may not be providing social support to the elderly. To improve the overall level of social support to the elderly, one should focus on the development of support resources available outside the family, as well as exploit potential support from relatives, colleagues, friends, medical staff, and other patients. There is an imperative demand for clinicians to strengthen clinical guidance for providing psychological counseling and emotional support in addition to the treatment of diabetes and its complications. Community nurses and physicians should provide reliable information and emotional support to the elderly through lectures and psychological interventions.
Diabetes is a disease requiring long-term treatment, which also requires patients to control their diet and self-monitor their blood glucose level. Therefore, self-management of diabetes is of vital importance. In this study, the standard score of self-management behavior was 66.32; the top three self-management dimensions with poor score index were exercise (60.8%), blood glucose monitoring (50.1%), and hyperglycemia/hypoglycemia management (40.8%). The proportion of patients with good diet control, regular exercise, medication management, blood glucose monitoring, foot care, and hyperglycemia/hypoglycemia management was 16.1%, 5.8%, 38.2%, 19.4%, 20.8%, and 31.3%, respectively. These results indicated that engagement in physical exercise and blood glucose monitoring were weak in elderly patients with type 2 diabetes mellitus [27].
Elderly patients with type 2 diabetes mellitus had moderate quality of life (-29.25 ± 24.41); poorly scored dimensions of quality of life were “Psychological feeling” (-8.67), “Activity (-6.36),” and “Emotion’ (-6.12). At the same time, 82.66% of patients reported complications, indicating that the quality of life in elderly patients with type 2 diabetes mellitus in China is poor [33]. This was consistent with the findings of previous studies [14, 47]. Interestingly, the group with low social support (score = -44.66) and in that with poor self-management behavior (score = -40.71) had a score that was 43.66% and 39.71% lower than the average (score = -29.25), respectively. That is to say, elderly patients with type 2 diabetes mellitus may experience inadequate social support and poor self-management, which may affect quality of life.
Importance of FPG monitoring
Glycated hemoglobin (HbA1c), FPG, and PBG are the main clinical monitoring indicators for diabetes mellitus. HbA1c reflects long-term blood glucose control, which is essential to avoid diabetes complications [48]. The long-term balance of blood glucose in patients with diabetes is emphasized clinically, which may lead to misinterpretation and hypoglycemia events during treatment [49–51]. Although HbA1c was used as a control target for long-term blood glucose monitoring, it cannot reflect the level of instantaneous blood glucose. Moreover, it has been confirmed that blood glucose fluctuations in elderly patients with diabetes are extremely harmful. Changes in human blood glucose lead to changes in systolic and diastolic blood pressure, which is a great challenge for fragile blood vessels such as those of the elderly. Therefore, blood glucose fluctuation cannot be ignored in the elderly population. Regular blood glucose monitoring is key.
In this study, FPG was considered more suitable for blood glucose monitoring in elderly patients. First, FPG is closer related to HbA1c than PBG [52, 53]. PBG increases and decreases depending on FPG. From this point of view, the control of FPG is thought to be more effective than that of PBG, for the former serves as the basis of individualized treatment. Second, the LANMET study has suggested that FPG has a linear relationship with HbA1c, and HbA1c increases with increased FPG and decreases with decreased FPG. A level of FPG of 5.6 mmol/L promotes HbA1c 7% to reach the target [54]. Thirdly, FPG is a major determinant of cardiovascular disease [55–57]. The recurrent fluctuation of FPG will lead to frequent hypoglycemia, cause an abnormal increase in sympathetic nerve excitability, and increase the incidence and mortality of cerebrovascular diseases [58]. Carlene et al. found that each 1-mmol/l decrease of FPG was associated with a 21% lower risk of stroke and a 23% lower risk of ischemic heart disease [59]. Moreover, as FPG variability increases, all-cause mortality and cardiovascular disease mortality also increase [60, 61]. Therefore, this study focused on FPG.
In particular, 9% of elderly patients with type 2 diabetes mellitus kept their FPG at a very strict level between 3.9 mmol/L and 5.6 mmol/L. However, it might be dangerous to multi-vulnerable patients because it might result in hypoglycemia, causing dysfunctional osmolality and a range of consequences [62], including death [63]. Therefore, the control of FPG should be not too strict to avoid the possibility of a hypoglycemia crisis. When hypoglycemia occurs and remains unnoticed for a certain period, irreversible body injury may occur [64]. It is of equal importance to keep close attention to both high and low FPG levels. This study showed that only 19.4% of patients had good self-management of FPG level. This should be listed as a priority target for intervention.
Mechanism of attention to FPG control
Correlation analysis revealed that the FPG level was negatively correlated with social support (r = -0.289, p < 0.01) and quality of life (r = -0.451, p < 0.01). The inverse association between FPG level and quality of life indicated that better FPG control level was associated with a higher quality of life and better social support. Further multi-mediation analysis results showed that social support exerted not only a direct effect on quality of life but also an indirect effect through the path SS→FPG→QOL (a2*b2). The standardized estimate was 0.2825 (p = 0.0014), indicating that FPG had a mediation role in the influence of social support on quality of life. The indirect effect of social support on quality of life through monitoring of FPG was significant.
The above study demonstrated that social support available from doctors, family, and friends was an important potential resource for diabetes interventions, which should be paid high attention. There is an urgent need to explore the effective way to mobilize more actively, timely, persistent, and greater social support from families and the society.
This study found that only 65.32% of elderly patients with type 2 diabetes mellitus were under the control of FPG, which was consistent with the findings of previous studies [18]. This might be explained by the path SS→FPG→QOL. With persistent and disease fluctuations and complications (82.66%), this could lead to poor quality of life. Their average scores were particularly poor in the psychological, activity, and emotional domains. Patients felt boresome, psychological and emotional fatigue, and more easily troublesome to talk and seek help from their family members or friends, resulting in their poor use of support. However, insufficient social support might, in turn, exert additional impact on FPG, and causing elderly diabetes patients more difficulty in keeping regular monitoring of blood glucose. Many patients measure only their blood glucose when they are not feeling well. Additionally, the long-term cost of regular self-monitoring blood glucose may also be very high for elderly patients. Therefore, mobilizing both external support (resources for regular monitoring) and subjective support (actions for regular monitoring) to achieve the target of monitoring FPG, preventing hypoglycemia, and improving the quality of life should be emphasized [65].
Mechanism of emphasis self-management activity
Correlation analysis showed that self-management behavior is positively correlated with social support (r = 0.323, p < 0.01) and quality of life (r = 0.369, p < 0.01). This is consistent with previous findings that better self-management activity is associated with a higher quality of life and better social support [12]. Further multi-mediation analysis results showed, in the path SS→SM→QOL (a1*b1), that the influence of social support through self-management behavior on quality of life was 0.2596 (p = 0.0042), indicating that self-management behavior played a mediation role in the influence of social support on quality of life. The indirect effect of social support on quality of life through self-management behavior was significant. That is to say, self-management behavior is an important promoting factor, which can positively contribute to the influence of social support on quality of life. One possible explanation is that self-monitoring of blood glucose is an important part of diabetes treatment. It is an important basis for doctors to formulate a hypoglycemic program for patients and an important reference for patients to observe blood glucose changes, which can effectively avoid the occurrence of hyperglycemia and hypoglycemia. As an important mediator, it can either enhance or reduce the impact of social support on quality of life, which highlights the value of improving self-management activity among elderly patients with type 2 diabetes mellitus.
However, this study showed that only 15.94% of patients had high-quality self-management, while 84.06% had moderate or poor self-management; moreover, more than 20% of patients reported inadequate social support. The study found that elderly patients with type 2 diabetes mellitus were unable to self-manage their health, including physical exercise and diet, which could contribute to poor quality of life. Previous studies have mentioned the need for dietary and medication guidance [66, 67]. However, our study found that exercise and mental health guidance for the elderly are still inadequate. Hence, to improve the quality of life in elderly patients with type 2 diabetes mellitus, doctors are required to educate their patients about self-management. Guidance on regular exercise, self-blood glucose monitoring, and management of hypo/hyperglycemia should be provided during routine appointments.
A relationship between FPG level, self-management, and quality of life was also observed. Correlation analysis revealed that FPG level was negatively correlated with self-management behavior (r = -0.322, p < 0.01). Further multi-mediation analysis results showed, in the path SS→SM→FPG→QOL (a1*a3*b2), that the standardized estimate was 0.1128 (p = 0.0029). This indicated that the mediation path was established in that order.
The indirect effect of self-management behavior on quality of life through FPG was significant. Poor self-management behavior might result in non-timely monitoring of the FPG level, which, in turn, might reduce quality of life. Glycemic control is partly dependent upon the regular completion of several self-management behaviors, including exercise, dietary modification, foot care, self-monitoring of blood glucose, and medication adherence. Attention to tailored social support targeted at the weakest areas of self-management, especially FPG control, should be strengthened.
Limitations of research
This study had a few limitations. First, as a cross-sectional study, the relationships between variables were only correlative, and causal relationships could not be established. Second, this study was performed at Heilongjiang province, and patients were recruited from city communities. Therefore, the findings of this study might differ from those of rural areas. Third, the MSPSS and 2-DSCS were revised in this study. Hence, the reliability of the scales requires further validation, despite good internal consistency. Fourth, this study focused on perceived social support by elderly patients. Actual social support was not analyzed. With the development and abundance of social support resources, a specific social support scale for elderly patients with type 2 diabetes mellitus should be developed. In this study, some patients had difficulty in understanding some questions from the CN-ADDQOL, for the scale needs further modification. Further studies with a larger, more diverse sample and more variables such as actual social support and specific self-management are needed.