Relationship Between Salt Intakeand Lipid Metabolism In Patients With Type2Diabetes

BackgroundType2diabetes has become a serious public disease and threated to people’s health inchina,and often clustered with dyslipidemia,hypertension,obesity and other diseases,which willsignificantly increase the risk of cardiovascular events when two or more factors coexisted.Compared with the general population,the epidemiological survey showed that the subjectswith hypertension are more prone to develop diabetes,affecting up to75%of type2diabeticpatients[1].Thus, hypertension and diabetes may have some common underlying relationshipand coexistent risk factors.Smoking,obesity,age are the common risk factors for bothhypertension and type2diabetes[2][3]. Long-term high salt intake have also been associatedwith hypertension[4], the prospective studies have also suggested that high sodium intakeincreased the risk of type2diabetes, independently of other risk factors including physicalinactivity, obesity and hypertension[5]. Therefore,high salt intake may be a new risk factor fortype2diabetes, whether high salt intake increased the risk of lipid disorders in patients withtype2diabetes remains unclear.24h urinary sodium was a common method to estimate dietarysalt intake in clinical epidemiology[6]. The aim of this study was to assess whether daily saltintake measured by24-h urinary sodium excretion, was related to lipid metabolism inpatients with type2diabetes,and further clarified the effect of high salt intake on lipidmetabolism in patients with type2diabetes. Research objectWe collected patients in the Department of Hypertension and EndocrinologywithDaping Hospital affiliated to Third Military Medical University from September2012toJuly2013,the patients with Type2diabetes aged from30to70years,200cases wasincluded,comprised112men and88women. According to the standard diagnostic with theedition of Type2Diabetes Prevention Guideline in China in2010: symptoms of diabetesplus random plamas glucose≥11.1mmol/L, or fasting plamas glucose FPG≥7.0mmol/L, or2h plasma glucose after glucose load≥11.1mmol/L, excluding subjects with hypertension,type1diabetes,special type of diabetes, acute metabolic disorder status,liver and kidneydysfunction,Serious cardiovascular and cerebrovascular disease,pregnant or lactatingwomen,using diuretics or lipid-lowering drugs,hemp drugs and drug-dependent users.MethodsWe collected general information,such as age,sex,duration of diabetes,drugtreatmentetc.specially trained person measured height, weight, waist circumference andblood pressure according to the WHO project.weight/height2was used to calculate bodymass index(BMI).Total cholesterol,triglycerides,low density lipoprotein cholesterol,highdensity lipoprotein cholesterol,apolipoproteinAl,apolipoproteinB,serum sodium,alanineaminotransferase,aspartate aminotransferase,uric acid,blood creatinine,fasting plamasglucose,and24h urinary sodium and potassium,urine creatinine,microalbuminuria of all thesubjects were detected. Daily salt intake measured by24h urinary sodium excretion weredivided into four quartiles as lowest salt intake group(<7.99g/d),middle salt intake group(7.99g/d~11.31g/d), higher salt intake group(11.31g/d~15.41g/d), highest salt intakegroup(≥15.41g/d)to compare related indicators.There is no subject of BMI less than18.5kg/m2,referred to Chinese diabetes prevention guideline of obese diagnostic criteria in2010,BMI divided into normal group(18.5~23.9kg/m2),overweight groups (24~27.9kg/m2),obese group (≥28kg/m2). The diagnosis of hypertriglyceridemia used fasting plasmaTG≥1.7mmol/L as a diagnostic cut-off point.Statistical analyses Values are expressed as the mean±standard deviation,count dataused composition ratio(%),non-normal distribution of measurement data used the median M(P25~P75),after changing into normal distribution data for analysis.Four groups were analyzed by ANOVA,compared rates used to χ2test, hypertriglyceridemia risk factors usedby Logistic regression analysis. Statistical significance was considered to be P<0.05. Allstatistical analyses were performed with SPSS for Windows18.0.Result1)The subjects were classified according to the quartiles of salt intake to comparebaseline parameters,there was a significantly increased in body weight,waist circumferenceand BMI.There was no significant difference in age,duration of diabetes,sex and drugtreatment among groups.2)Compared the biochemical indicators with four groups,fasting plasma glucose,24hurinary potassium was significant difference (P <0.05), the level of fasting plasma glucosein lower salt intake group was significantly higher than that in the highest groups (P=0.007),the level of24h urinary potassium in highest salt intake group was significantly increasedthan in other groups(P=0.001).3)There was an increasing trend in triglycerides with salt intake.The concentration ofplasma triglyceride was significantly higher in the highest salt intake compared with that in thelowest group(P=0.015).butTC,HDL-C,LDL-C,ApoA1,ApoB were no statistical significanceamong groups.4) The level of24h urinary sodium was significantly higher in obese group than thenormal group (P=0.018),there was no significant difference between normal and overweightgroups,overweight and obese groups.5)One-way ANOVA analysis showed that the level of triglyceride in overweight groupwas significantly higher than that in normal group(P=0.010), obese group was significantlyhigher than normal group (P=0.017), there was no significant difference betweenoverweight and obese groups.6）Logistic regression analysis showed that24h urinary sodium, weight, fastingplasma glucose was an independent risk factor of hypertriglyceridemia in patients with type2diabetes.Conclusion:High salt intake is an important risk factor for hypertriglyceridemia in patients with type2diabetes，while high salt intake may increase the incidence of obesity,reducedsodium intake may improve the lipid metabolism disorders in patients with type2diabetes，and prevent the development of diabetes complications.