Case Report: Overlap of long QT syndrome and catecholaminergic polymorphic ventricular tachycardia in two Chinese children with CALM2-related calmodulinopathy.

Diabetes is a very common chronic metabolic disease in the world, and its prevalence is increasing, which has become a serious public health problem (). Diabetes not only affects the disorder of blood glucose control and metabolic balance, but also is often accompanied by significant mental and psychological comorbidities (). Among these psychological problems, depression is the most common mental complication in patients with diabetes (). According to epidemiological data, the risk of depression in diabetic patients is 2–3 times higher than that in non-diabetic patients. About 20%–30% of diabetic patients have comorbid depression, which is much higher than 5%–10% of the general population (). This situation of diabetes combined with depression is not accidental ():on the one hand, diabetic patients are prone to induce or aggravate depression when they face the pressure of disease management, the potential threat of complications and many restrictions of lifestyle for a long time (); on the other hand, depression further deteriorates blood glucose control and increases the risk of diabetes-related complications and mortality by activating the hypothalamus-pituitary-adrenal axis, promoting the release of inflammatory factors, and reducing treatment compliance (). Diabetes and depression interact with each other and form a vicious circle, which not only greatly reduces the quality of life of patients, but also brings a heavy burden to society and economy (). At present, the common treatment mode of diabetes mellitus complicated with depression is “hierarchical management”: hypoglycemic drugs to control blood glucose, antidepressants or psychotherapy to deal with emotional problems (). However, in the actual clinical treatment process, there are many problems. First of all, some hypoglycemic drugs () (such as insulin, sulfonylureas) may cause patients to have a fear of hypoglycemia, which in turn indirectly aggravates anxiety and depression. Secondly, the use of traditional antidepressants () (such as tricyclic antidepressants) in patients with diabetes has been limited due to adverse reactions such as weight gain, increased insulin resistance, and arrhythmia. Third, although psychotherapy () (such as cognitive behavioral therapy) has a certain effect, it is difficult to popularize and apply in a wider range due to the difficulty of obtaining professional psychotherapy resources, long treatment cycle and relatively high treatment cost. Selective serotonin reuptake inhibitors (SSRIs) are the current first-line antidepressants, which exert antidepressant effects by blocking 5-HT reuptake and enhancing central 5-HT neurotransmission (). Compared with traditional antidepressants, SSRIs have better safety and tolerance: less sedative and anticholinergic adverse reactions (dry mouth, constipation, blurred vision), little effect on cardiac conduction, and relatively high safety in the case of drug overdose (). For diabetic patients with depression, SSRIs may have some unique theoretical advantages: First, don’t increase the risk of hypoglycemia (most studies did not report severe hypoglycemia events); Second, some SSRIs (such as sertraline and fluoxetine) had neutral or mild beneficial effects on body weight and glucose metabolism. Third, it can improve the physical symptoms associated with diabetes (such as fatigue, appetite changes, sleep disorders) (, ). However, the existing clinical studies on the application of SSRIs in diabetic patients with depression have some limitations. The sample size of these studies is generally small, the follow-up time is short, the outcome indicators used are different, and the impact on patients’ anxiety symptoms and metabolic indicators is not fully reported. These factors make the efficacy and safety of SSRIs in this special patient population still controversial.