Increased subcutaneous fat

Introduction Obesity refers to obesity when the body's excess fat content is caused by various reasons and significantly exceeds the normal average amount of normal people. The fat stored under the skin accounts for about 50% of the total fat. Obesity can occur at any age, is more common in middle-aged people, and more women than men. The weight gain of obese people is due to the increase of adipose tissue, while the muscle tissue does not increase or decline, but the athletes' muscles are particularly developed, or the weight gain of edema is not included. When the calorie intake exceeds the body's consumption, the excess calories are stored in the body in the form of fat, so that those who weigh more than 20% of the standard weight are obese, more than 10% are overweight; and according to height and weight, the body mass index (weight team) Kg / height (m2) is calculated, more than 24 is obese. The World Health Organization (WH 0) standards are: men > 27, and women > 25 are obese.

Cause

Etiology classification

Divided into two categories: simple obesity and secondary obesity:

(1) Simple obesity

No obvious endocrine, metabolic diseases can be found.

1. Constitutional obesity: also known as juvenile onset obesity.

2. Acquired obesity: also known as adult onset obesity.

(two) secondary obesity

There are obvious causes such as endocrine and metabolic diseases.

Hypothalamic encephalopathy

(1) Hypothalamic syndrome: various causes such as sequelae of inflammation, trauma, tumor, granuloma, etc. can lead to hypothalamic syndrome obesity.

(2) Obesity reproductive incompetence: also known as Frohlich syndrome.

2. Pituitary disease

(1) pituitary ACTH cell tumor: also known as Cushing's disease.

(2) pituitary growth hormone (GH) cell tumor: also known as acromegaly.

(3) pituitary prolactin (PRL) cell tumor

3. Hypothyroidism

(1) Primary (thyroid) hypothyroidism.

(2) hypothalamic-pituitary hypothyroidism.

4. Islet disease

(1) Non-insulin-dependent (NIDDM, type 2) early diabetes.

(2) insulinoma: also known as islet B cell tumor.

(3) Functional spontaneous hypoglycemia.

5. Adrenal hyperfunction is also known as hypercortisolism, Cushing's syndrome.

6. Hypogonadism

(1) Female menopausal obesity.

(2) Polycystic ovary syndrome.

(3) Men have no testis or no testicular disease.

7. Other

(1) Painful obesity (Dercum disease).

(2) Sodium hydroxide retention obesity.

(3) Intracranial plate hyperplasia (Morgagni-Stewart-Morel syndrome).

(4) Sexual naive-retinal retinitis-multi-finger (toe) malformation syndrome (Laurence-Moon-Biedl syndrome).

8. Drug-induced obesity Psychosis patients who take long-term use of chlorpromazine, long-term use of insulin in certain diseases, promotion of protein synthesis preparations, glucocorticoids, and cisplatin can cause appetite and lead to obesity.

an examination

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First, medical history

1. Ask the patient's eating habits and exercise: a rough calculation of the daily intake of calories, too much diet and too little activity is the main external cause of simple obesity.

2. Ask family history: Patients with simple obesity often have parental obesity. Their brethren and patients are also obese at first age. Family habits are more like sweets, more food and more times, and more snacks. .

3. Understand personal birth history and physical development status, secondary sexual development and sexual function status. Simple obesity patients have no secondary sexual development disorder, sexual function is more normal, and secondary obesity patients have second. Sexual developmental disorders and sexual dysfunction. In addition, should ask about the past health conditions, with or without meningitis, encephalitis, craniocerebral trauma, history of cancer, because of secondary obesity have a clear cause, obesity is only one of its clinical manifestations, especially pay attention to the presence or absence of nerves History of mental illness, endocrine and metabolic diseases, such as hypothyroidism, hypercortisolism, giant disease and acromegaly, hirsutism, hypothalamic syndrome, and other history.

Second, physical examination

1. Measure the patient's height (m), weight (kg), body temperature, blood pressure, abdominal circumference and hip circumference to understand whether the patient is obese or not, and whether there is abnormal temperature regulation (hypotial dysregulation during hypothalamic syndrome) And blood pressure is elevated.

The diagnosis of obesity is mainly based on excessive accumulation and/or abnormal distribution of fat in the body.

(1) Body mass index (BMI): is a commonly used measure. Body mass index (BMI) = weight (kg) / height (m) 2. WHO proposes that BMI 25 is overweight and 30 is obese. The Asia-Pacific Diabetes and Overweight Diagnostic Criteria Symposium is based on the fact that Asians tend to have abdominal or visceral obesity when they have a relatively low BMI and show a significant increase in the risk of hypertension, diabetes, hyperlipemia and proteinuria. Therefore, BMI 23 is considered to be overweight, and BMI 25 is obese.

(2) Ideal weight ideal weight (kg) = height (cm) -105; or height minus 100 and then multiplied by 0.9 (male) or 0.85 (female). Those who actually weigh more than 20% of their ideal body weight are obese; more than 10% of the ideal body weight and less than 20% are overweight.

(3) The distribution characteristics of body fat can be measured by waist circumference or waist-to-hip ratio (WHR). The waist circumference is the distance from the midpoint between the rib line of the midline and the anterior superior iliac spine; the hip circumference is the distance measured by the most bulging part of the buttocks, and the waist-to-hip ratio (WHR) is the ratio of the waist circumference to the hip circumference. Waist male 90cm, female 80cm; waist-to-hip ratio WHR> 0.9 (male) or > 0.8 (female) can be regarded as central obesity.

(4) The degree of subcutaneous fat accumulation can be estimated from the thickness of sebum. The average thickness of scapular sebum in normal 25-year-old is 12.4 mm, which is more than 14 mm for excessive fat accumulation. The thickness of triceps in the triceps is: 10.4 mm for males at 25 years old. The average is 17.5mm.

(5) Visceral fat can be measured by B-mode ultrasound, dual-energy X-ray absorptiometry, CT scan or magnetic resonance. After determining obesity, it should be identified as simple obesity or secondary obesity.

2. Observe the body shape and fat distribution: in patients with simple obesity, male fat is distributed in the neck and head. The trunk is the main part; the female is mainly the abdomen, lower abdomen, chest breasts and buttocks. Secondary obesity varies with different diseases, such as heart-to-heart obesity, full moon face, buffalo back, multi-blood appearance, purple pattern. Acne is characteristic of hypercortisolism; females are obese and hairy. Amenorrhea infertility may be caused by polycystic ovary. Obesity, facial swelling, dry and rough skin, and unresponsiveness are characteristic of hypothyroidism. The extremities of the extremities are fat and the face is ugly and characterized by acromegaly.

3. Vision and visual field examination: hypothalamic and pituitary obesity, especially in this part of the tumor can cause visual impairment, hemianopia and so on. Detailed physical examination is the main clue for the diagnosis of the cause of secondary obesity.

Third, buy a laboratory inspection

(1) Laboratory testing of hypothalamic and pituitary functions

1. Hormone determination ACTH, FSH, LH, TSH, GH, PRL measurement, in order to understand the hypothalamic and pituitary function, the diagnosis of hypothalamic and pituitary obesity.

2. TRH, LH-RH excitation test:

(1) TRH stimulation test: Intravenous injection of TRH200~500 g in the morning, and TSH levels were measured before injection and at 15, 30, 60, and 90 min after injection. Serum TSH peaked in normal people 30 min after injection, reaching 10~30 g /L. There is no increase in TSH in hyperthyroidism (no response). The baseline value of serum TSH is increased in primary hypothyroidism. The TSH value is significantly increased after intravenous injection of TRH (significant excitability); secondary hypothyroidism such as lesions in the hypothalamus, TRH TSH was significantly increased after stimulation; if the lesion was in the pituitary gland after TRH stimulation, TS H did not increase. Pituitary tumor, Xihan syndrome, advanced acromegaly and other pituitary diseases caused insufficient secretion of TSH, serum TSH levels were low, and the response after TRH stimulation was poor, suggesting that the pituitary TSH reserve function was poor.

(2) LH-RN (LRH) stimulation test: differential hypogonadism is primary or secondary. At 8 o'clock in the morning, LRH 100 g was injected intravenously, and LH was taken before injection and at 15, 30, 60 min after injection; then, LRH 100 g was intravenously injected (or intramuscularly) every other day for 3 times, and the above test was repeated. In normal women, the peak of LH appeared 15 minutes after injection, which increased to more than 3 times of the baseline value, and the absolute value increased by 7.5 nmol/L or more, which was twice as low as that of females. In patients with low primary dysfunction, the LH base value is increased. The peak value of LH after injection of LRH is 4-5 times higher than the baseline value. (The reaction is obvious in humans with pituitary lesions. The LH base value is low. After LRH injection, the response is poor or no reaction. In the thalamus, the LH has a low baseline value and a normal or delayed response after LRH injection (peak occurs 60 or 9 min after LRH injection)

(B) Determination of peripheral gland hormones

1. Thyroid hormone determination TT3, TT4, FT3, FT4 determination to understand thyroid function.

2. Determination of adrenocortical hormone: blood cortisol, 24h urine 17-hydroxysteroids and 17-ketosteroids, 24 h urinary free cortisol determination, the diagnosis of cortisol-induced obesity. In the early stage of hypercortisolism and simple obesity identified by the above-mentioned tests, a small dose of dexamethasone (2mg / d) inhibition test should be performed, the former is not inhibited.

3. Islet function test

(1) Fasting and postprandial 2h blood glucose measurement: It is necessary to do oral glucose (75 g) tolerance test (OGTT) to help diagnose diabetes (DM) and impaired glucose tolerance (IGT).

(2) Determination of insulin and C peptide: it is helpful for the diagnosis of pancreatic obesity. In particular, the insulin release test can reflect the reserve function of islet B cells (in OGTT) while measuring plasma insulin concentration).

4. Determination of blood lipids.

5. Vertical position water test: shows that the patient has water retention when standing. After urinating in the morning on an empty stomach, the patient drank 1000 ml of water within 20 minutes, and then urinated once every hour for 4 hours to record the urine volume. On the first day, take the lying position (without the pillow), and take the standing position for the next day, such as the activity or the normal person's standing position, the drainage rate is 81.8+ 3.7% of the drinking water, and the urine output in the lying position is equal to the drinking water or even the drinking water. In the case of water retention obesity, the urine volume in the standing position is lower than the urine volume in the lying position by more than 50%.

Fourth, equipment inspection

(1) Inspection of obesity diagnosis methods

1. Diagnosis according to height and weight: firstly find the standard weight according to the patient's age (see the body standard weight scale), or calculate the following formula: standard weight (?) = "height (cm) -100" x 0.9, such as the actual patient An overweight of 20% of the standard weight can be diagnosed as obesity. However, factors due to muscle development or water retention must be excluded.

2. Skin wrinkle calipers measure subcutaneous fat thickness: 25-year-old normal shoulder swelling subcutaneous fat thickness averaged 12.4?, more than 14? for obesity; deltoid muscle sebum thickness male average price. 4mm, female 17.5? (normal person 25 years old value)

3. X-ray soft tissue filming calculation of skin fat thickness, ultrasonic reflection imaging method to estimate subcutaneous fat thickness and other methods (standard with caliper method)

4. Calculate body weight (kg) / body 2 (?) > 24 according to body mass index. World Health Organization standards: men > 27, women > 25 for obesity.

(2) CT, MRI

Diagnosis of hypothalamic, pituitary tumors, vacuolar sella, adrenal tumors, and insulinoma.

(3) B-mode ultrasound

It is helpful for the diagnosis of adrenal hyperplasia, tumor and islet cell tumor.

(d) 131I-19-Iodocholinol and computer program for adrenal scanning

It is helpful for the diagnosis of adrenal hyperplasia or tumor.

Differential diagnosis

Differential diagnosis of subcutaneous fat hyperplasia:

First, simple obesity

(1) Constitutional obesity (young onset obesity)

From childhood obesity to adulthood, there is a family history of obesity, good appetite, uniform distribution of body fat, hypertrophy of fat cells, poor diet and enhanced exercise, and less sensitive to insulin. No obesity can be found.

(2) Acquired obesity (adult onset obesity) is more than 20 to 25 years old, due to overnutrition, decreased activity and genetic factors, obesity, fat cell hypertrophy, no proliferation, diet control and exercise weight loss Well, the sensitivity of insulin can be restored after weight loss.

Second, secondary obesity

(a) hypothalamic obesity

1. Various causes of hypothalamic syndrome involve diseases caused by the hypothalamus.

(1) Etiology: 1 tumor is the most common, and there are 53 cases of tumors in 70 cases in China, including craniopharyngioma (25 cases), followed by pineal tumor (11 cases) and thalamic tumors in 6 cases. There were 4 cases of third ventricle tumor, 2 cases of ependymoma, 1 case of olfactory meningioma, gray nodule tumor, ectopic pineal tumor, saddle tumor and astrocytoma. There are reports of leukemia, metastatic cancer, hemangioma, adenoma, hamartoma, teratoma, plasmacytoma neurofibroma, ganglion cell, medulloblastoma, and sarcoma. Malignant hemangioendothelioma and the like. 2 infection and inflammation: tuberculous or purulent meningitis, viral encephalitis, epidemic encephalitis, meningitis, smallpox, measles, chickenpox, rabies vaccination, histoplasmosis, etc., 70 cases in China 6 cases of inflammation. 3 brain trauma, surgery and radiation therapy. 4 vascular lesions such as cerebral arteriosclerosis, cerebral hemangioma, systemic lupus erythematosus and other causes of vasculitis. 5 granuloma and degeneration become tuberculoma. Sarcoidosis, reticuloendotheliosis, eosinophilic granuloma. Chronic multiple xanthoma, nodular sclerosis, brain softening and gliosis. 6 acute interstitial hemoptysis, carbon dioxide anesthesia, oral contraceptives, chloropropionate reserpine caused by galactorrhea amenorrhea syndrome. 7 Mental trauma, functional disorders caused by environmental changes, etc.

(2) Clinical manifestations: Due to the small size and complex function of the hypothalamus, lesions often damage multiple nuclear groups and involve multiple physiological regulatory centers, which are characterized by complex clinical syndromes:

1 more food and obesity, due to lesions involving the hypothalamic ventromedial nucleus or nodules near, often accompanied by genital dysplasia (called obesity reproductive incompetent malnutrition, that is, frohlich syndrome, most people show drowsiness, even episodes of sleepiness Symptoms (Kleine-tevlll syndrome in patients with uncontrollable narcolepsy, can last for hours to days, wake up after overeating and obesity.

2 endocrine dysfunction, due to one or several hypothalamic release hormone or anterior pituitary hormone secretion disorder caused by hypersecretion or decline, such as sexual precocity or sexual dysfunction, female amenorrhea, male obesity, reproductive incompetence, sexual dysplasia and Olfactory loss syndrome; galactorrhea amenorrhea, hypercortisolism, hypothyroidism, acromegaly, giant disease, diabetes insipidus.

3 fever or hypothermia.

4 mental disorders such as crying and laughing, disorientation, hallucinations and paralysis.

5 hypothalamic epilepsy, headache, sweating or sweating, hand and foot hair group, sphincter dysfunction, vision loss, visual field 'deficiency and hemianopia, blood pressure fluctuations (suddenly high and low dilated pupil dilated. Diagnostic basis 1 has a history of eating more, lethargy, a variety of endocrine dysfunction, abnormal body temperature regulation, abnormal sweat secretion.

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