What Is the Dawn Phenomenon?

The "dawn phenomenon" refers to a kind of high morning sickness caused by the unbalanced secretion of various hormones at dawn (3-9 am) in the absence of hypoglycemia in patients with diabetic glycemic control at night. Blood sugar status. This phenomenon was first proposed by foreign scholar Schmidt in 1981.

Western Medicine Name: Dawn phenomenon
English name: DMDP
Disease site: Blood vessels, pancreas
The main symptoms: Fatigue, hunger, sweating, palpitations

Main cause: Imbalanced secretion between hormones
Multiple groups: Diabetics, healthy people
Contagious: Non-contagious
Whether to enter health insurance: no
Clinical treatment: INS treatment, SMS treatment

Dawn phenomenon crowd

Dawn phenomenon (DMDP) occurs in patients with diabetes and can also be seen in healthy people. It should be noted that the dawn phenomenon (DMDP) is distinguished from early morning hyperglycemia due to other causes, such as the increase in nocturnal basal blood glucose caused by hypoglycemic agents or nocturnal insulin (INS). Reactive hyperglycemia (Somogyi phenomenon) after nocturnal hypoglycemia. In addition to knowing if the patient has hypoglycemia such as fatigue, palpitations, hunger and sweating, how to use urine glucose and hypoglycemic agents before going to bed, monitor venous or capillary blood glucose every 1 to 2 hours at night, or use continuous glucose The monitor monitors the night blood glucose, draws a night blood glucose curve based on the night blood glucose, and makes a correct diagnosis. At present, micro-test strip blood glucose meters are mostly used to monitor finger capillary blood glucose at night, which is slightly higher than venous blood glucose and has a good correlation.

Possible mechanism of dawn phenomenon

1. Increased INS antagonist hormone levels and increased INS resistance

Some people have determined that the levels of serum growth hormone (GH), cortisol, glucagon, and catecholamines at dawn are higher in DMDP patients than in patients without diabetes mellitus (DM) without DP, and the use of drugs to inhibit the secretion of the antagonist hormones can control DMDP. Most studies have shown that early morning serum GH levels in DMDP patients are the main cause of DP. Some people have found that GH secretion in healthy elderly is significantly reduced, and its basal secretion is only 30% of young people, and no significant DP occurs.

2. The body's clearance and demand for INS increases

Some patients with IDDM and DP who are completely deficient in INS are continuously infused with glucose (GS) and INS at night, and it is found that the rate of INS infusion required to maintain their stable nocturnal serum INS level at dawn increases, that is, the body's clearance of serum INS Rate increases. Some people also use the GS clamp test to continuously infuse GS and INS at night in DMDP patients, and found that the amount of INS needed to maintain their stable blood glucose levels at night at dawn is increased, which may be related to the increase of INS antagonist hormone secretion and body at dawn. Increased clearance rate for INS.

3.Other

For example, the patient's mental state, awakening at dawn, and the depth of sleep can all affect the blood glucose level at dawn; there are many other studies that have shown that DP exists in normal people, suggesting that DP in DM patients is only an enlargement and clarity of normal physiological processes And it is a manifestation of dysfunction of blood glucose compensatory regulation in patients with DM.

Liming phenomenon clinical treatment

Dawn phenomenon general treatment

Eliminating the mental burden of patients, improving and deepening sleep, reasonable diet, exercise therapy and the use of hypoglycemic agents, improving the sensitivity of INS, etc., are all conducive to the control of DMDP.

INS Dawn phenomenon INS treatment

Application of fast-acting INS

Some people use the fast-acting INS before breakfast subcutaneous injection (SC) and breakfast before dawn at DMDP patients, and some people have achieved some effects before the dawn by intramuscular injection of fast-acting INS or continuous intravenous drip of fast-acting INS at night. Inconvenience is not easily accepted by patients; the better method is to increase the amount of fast-acting INS at dawn at the time of continuous subcutaneous insulin injection (CSII) treatment, but the lack of open-loop CSII for continuous blood glucose monitoring is prone to hypoglycemia, and the price of closed-loop SCII Expensive and difficult to promote.

Application of Medium Efficiency INS

Before dinner (17:30) SC medium-effect INS Some people have SC medium-effect INS before dinner to effectively control DP in DM patients. Most of them use Monodard and Lente with longer duration of peak effect. Hyperglycemia is more conducive to the control of DMDP.

Before midnight sleep (21:00) SC mid-effect INS Some people successfully treated DM before midnight sleep.

The DP of the patient is significantly better than that before the dinner. Monotard or Lente can be used, even NPH with a short peak duration. On the premise of fixed diet and activity and the type and dose of INS, the original NPH dose of SC before dinner in DP IDDM patients was shifted to night before sleep. SC successfully controlled DMDP, which may be related to the shift to the dawn after the peak of NPH effect. .

According to the time and severity of DP indicated by the night blood glucose curve of DMDP patients, the medium-acting INS whose peak of action coincides with the time of DP and its injection time are selected and the injection dose is adjusted. You can also refer to the medication habits of DMDP patients to choose an injection regimen.

Application of long-acting INS

Some people have SC long-acting INS-PZI or Ultralente before breakfast to treat patients with DMDP, and Ultralente is the first choice.

For the application of high-purity INS, select high-purity, low-antigenic INS to increase the sensitivity of INS and reduce the formation of INS antibodies. Monomodal (MP) or single-component (MC) INS can be selected. Well, patients with better economic conditions can choose non-antigenic human INS.

(SMS) Dawn phenomenon somatostatin (SMS) treatment

The earliest people found that continuous intravenous drip of fast-acting SMS at night can inhibit GH secretion in DM patients at dawn to treat their DP and eliminate hyperglycemia in the morning. However, due to the short duration of fast-acting SMS, it is inconvenient to administer, and it affects many endocrine systems. Gastrointestinal side effects, etc., make its clinical application limited. Since then, long-acting SMS has been developed and applied for DP. Navascues et al. Had given patients SC100mg SMS201-995 (Sandostatin) before bedtime to successfully control DP in patients with IDDM; Campbell et al. Used long-acting SMS (L363586) 600mg intranasal administration before bedtime could also effectively reduce nighttime GH in IDDM Levels and early morning hyperglycemia. Therefore, long-acting SMS is becoming an effective drug for the treatment of DMDP.

Dawn phenomenon anticholinergic drug treatment

Anticholinergic drugs can also inhibit GH secretion to treat DMDP. Davidson et al. Gave 8 patients with IDDM orally 5 mg of methyl scopolamine at 22:30 at night, showing that their 24-hour blood free fatty acid levels were reduced and early morning hyperglycemia was controlled, but it may induce or aggravate dysuria in patients with DM autonomic neuropathy Or increase in residual bladder urine and side effects such as flushing and faster heart rate. Selective gastric vagus nerve blocker can avoid the above-mentioned side effects, and it is more widely used in clinical practice. Many studies have found that piperenzepine can successfully inhibit nocturnal GH secretion in IDDM patients and control patients' early morning high blood sugar. The methods are mostly to take 100mg ~ 150mg orally before bedtime or to inject 20mg intravenously within 15 minutes. The effect of oral administration is better.

Dawn phenomenon metrapidone treatment

Increased midnight cortisol secretion and enhanced INS antagonism are also one of the main reasons for DMDP. Atiea gave 7 patients with NIDDM orally with metyrapone 30mg / kg body weight at 24:00 midnight, and their blood cortisol and blood glucose decreased significantly at dawn. , Effectively control the DP of NIDDM patients, but long-term medication may occur adrenal insufficiency.

Dawn phenomenon cyproheptadine treatment

Some people in China have treated 18 cases of DMDP with cyproheptadine at 12-16mg / d, and found that the GH and cortisol levels of patients were reduced at 7:00, which effectively treated DMDP. The mechanism may be that cyproheptadine through its strong antihistamine Antagonizing the effect of serotonin inhibits GH and ACTH secretion from the anterior pituitary gland and reduces early morning hyperglycemia.

In short, DMDP is caused by the body's increased secretion of INS antagonist hormones and the clearance and demand for INS at dawn; its treatment methods are many, including SC intermediate-acting INS before dinner and before bedtime and using long-acting SMS, selectivity Gastric vagus nerve blocker, piperazine, has good curative effect and is easily accepted by patients.