| Objective: With the rapid development of economy, people's dietary structure has significantly changed, with an over-intake of fat-containing food.Glucose and lipid metabolic dysfunction has become more and more common.Our previous research found that the serum free fatty acid increases in patients with impaired glucose tolerance, especially serum saturated fatty acid is significantly increased in these patients. The increase in free fatty acid plays important role in the development of insulin resistance. Therefore, it is meaningful to study the risk factors of increasing free fatty acid for improving glucose metabolism dysfunction and insulin resistance.Recent research on thyroid function indicates that serum levels of thyroid hormones can influence the regulation of lipid metabolism. It is widely recognized that patients with hypothyroidism have lipid dysfunction including increased serum cholesterol levels. It is also found that subclinical hypothyroidism is often accompanied with an increase in total cholesterol(TC), low-density lipoprotein cholesterol,(LDL- C) in serum increased and a decrease in serum high density lipoprotein cholesterol(HDL- C). Recent researches also indicate the association of thyroid hormone with serum lipid.However, the relationship between thyroid function and free fatty acids is less investigated. Especially, the correlation of serum thyroid hormone and free fatty lipid in patients with different glucose tolerance is less studied.The present research chose healthy people, people with glucose intolerance and diabetes patients. Serum lipids, free fatty acid(FFA), thyroid function, glycosylated hemoglobin, fasting insulin, insulin resistance index and blood lipid were detected. The correlation between FFA and TSH, FFA and insulin resistance, as well as TSH and cholesterol were studied. The correlation of serum free fatty acid and thyroid function status in people withdifferent glucose tolerance was investigated.Methods: Oral glucose tolerance test with a 75 g of glucose load was proceeded in all subjects. All subjects were divided into normal glucose tolerance group(group A), abnormal glucose tolerance group(group B) and type 2 diabetes mellitus group(group C). Patients with impaired fasting glucose(IFG) were IGT goup. Diagnostic criteria of type 2 diabetes was in accordance with type 2 diabetes of the WHO diagnostic criteria in1999.HOMA insulin resistance index- IR = fasting blood glucose(FBG,tendency for L) × fasting insulin(FIns, m IU/L) / 22.5. Free fatty acid was detected with Elisa kits. Blood glucose, blood lipids and other parameters were analysed by automatic biochemical analyzer. Serum insulin and thyroid hormones were detected by Electrochemical luminescence method. Glycated hemoglobin were detected by high performance liquid chromatography. Data were analysed by SPSS18.0 software.Results:1 Diabetes-related index changes in patientsGlycated hemoglobin in group A, group B and group C were statistically different. The difference between group A and group C was statistically significant(P < 0.05). FINS: 8.39 ± 6.43 u U/ml in group A and 11.87±5.96 u U/ml in group B and 11.93 ±12.67 u U/ml in group C. Fasting insulin were gradually increased in 3 groups. Compared with group B, group C were statistically significant(P< 0.05), while no significant difference was found between group B and group C. HOMA- IR: group A 2.00 ±1.84 group B2.99±1.55, group C 4.45±5.05. There are significant difference both between group A and group B and between group A and group C.: group A96.21±53.60,group B 126.60±111.62, group C 66.92±82.42. The difference between group A and group B was statistically significant(P< 0.05). HOMA-beta in group C was significantly lower,compared with group A and group B(P< 0.05).2 Blood lipid index changes in 3 groupsFFA: group A 54.21±19.18 pg/ml,group B 71.28 ±42.55 pg/ml, group C71.39 ±26.82 pg/ml. FFA in group A was significantly lower compared with group B and group C(P < 0.05). There was no significant difference between diabetes and abnormal glucose tolerance group(P > 0.05). Total cholesterol:group A 4.68±0.79 mmol /L,group B 5.05 ±0.89 mmol /L, group C 4.81 ±1.07mmol/l. There was significant different between group A and group B; while there was no statistically significant difference between group B and group C.High-density lipoprotein cholesterol: group A 1.52 ±0.39 mmol/l, group B1.30 ±0.30 mmol /l, group C 1.02 ± 0.26 mmol/l. Low density lipoprotein cholesterol: group A 2.53 ± 0.74 mmol/l, group B 3.61±0.82 mmol /l, group C3.16 ±1.01 mmol /l. There was significant difference between group A and group B(P < 0.05).3 Changes in serum hormones related to thyroid function in 3 groupsTSH: group A 2.05±0.88?IU/ml,group B 2.48±1.54?IU/ml/ml, group C1.76± 0.85?IU/ml; the difference between group A and group B was statistically significant(P < 0.05). TT3: group A 1.80± 0.36 nmol/l,group B1.95±0.89 nmol/l, C group 1.67±0.30 nmol/l; there was no statistical difference between group A and group B(P> 0.05), while the difference between group C and group B was statistically significant(P< 0.05). TT4:group A 104.47±23.92 nmol/l,group B 109.21± 24.20 nmol/l, C group92.85±31.62 nmol/l.There was no statistical difference between group A and group B(P > 0.05), while the difference between group C and A, B group was statistically significant(P< 0.05).4 The correlation of free fatty acids with thyroid stimulating hormoneUnder different glucose tolerance status,serum free fatty acids and thyroid-stimulating hormone were positively correlated, r = 0.671, p < 0.05).At the same time, free fatty acid is negatively related to the high density lipoprotein cholesterol(HDL-c),(r = 0.141, P< 0.05). Free fatty acid is positively related to low density lipoprotein, r = 0.157, P< 0.05). Blood thyroid-stimulating hormone is negatively related to the glycosylated hemoglobin,(r = 0.181, P< 0.05). Thyroid stimulating hormone is positively related to total cholesterol,(r = 0.172, P < 0.05).Conclusion:1 Serum free fatty acids increase in people with impaired glucose tolerance.2 The rising of serum free fatty acids and thyroid-stimulating hormone is correlated in people with impaired glucose tolerance. |
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