Biomedical Research

Research Article - Biomedical Research (2017) Volume 28, Issue 6

The study on relationship between obesity and living quality or incidence of T2DM complication: 3 year Chinese cohort study

Fan Linlin*, Liu Yaping, Yu Jixiang, Lu Ying, Zhao Jie, Sun Fengjuan, Mi Na and Wu Junli

Department of Endocrinology, Jining City First People's Hospital, China

*Corresponding Author:
Fan Linlin
Department of Endocrinology
Jining City First People's Hospital, China

Accepted date: November 1, 2016

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Abstract

Objective: To evaluate the impact of obesity on the living quality and the complications risk in T2DM patients.

Methods: A total of 1000 patients with T2DM were observed for a median follow-up period of more than 3 years (less than 4 years). In the cohort, there were 500 patients who were obese (30 kg/m2) as obesity group, and other 500 normal weight (18.5 kg/m2) patients who were paired with the obesity group (non-obesity group). The living quality and incidence of complication in the follow-up period between two groups was compared. Relative risk of T2DM complications between two groups was calculated.

Results: The patients in Non-obesity group had better score than those in the obesity group (P<0.05). We follow up the primary complications of all the patients. The result showed that the incidence in the obesity group was significantly higher in the comparison of cerebrovascular (19.80% vs. 10.40%, t=17.23, P<0.05), peripheral artery (17.40% vs. 8.60%, t=17.12, P<0.05), cardiovascular (14.00% vs. 7.60%, t=10.63, P<0.05) and renal (9.20% vs. 5.60%, t=4.73, P<0.05) complications. Moreover, patients in the obesity group have higher risk in the cerebrovascular (RR=5.58, 95% CI ((3.58~9.25)), peripheral artery (RR=5.49, 95% CI (3.40~8.59)), cardiovascular (RR=2.25, 95% CI (1.29~5.43)) and renal complications (RR=2.10, 95% CI (1.18~5.06)) than that in the non-obesity group.

Conclusions: T2DM patients with obesity will have great possibilities poor outcome in living quality; T2DM patients with obesity will have higher risk in diabetes complication.

Keywords

Type 2 diabetes mellitus, Complication, Obesity, Follow-up.

Introduction

Type 2 diabetes mellitus (T2DM) is a metabolic disorder caused by many factors. It is clinical incurable in the stage. The core strategy is to control blood sugar and delay complications [1-3]. The ultimate goal is to develop the patients’ quality of life. Due to the long course of T2DM, patients’ psychological, physical and social functions are closely correlated with the living quality of T2DM patients [4,5]. After these potential confounding factors are adjusted, obesity is still an independent risk factor for reducing the living quality of T2DM patients [6,7]. Obesity as an epidemic of this and last century is a major public health problem worldwide which its prevalence is dramatically increasing in this century [8,9]. Obesity is physiologically defined as fat accumulation in an abnormal or excessive pattern in adipose tissue may cause some serious health concerns, including the poor outcome in some disease [10]. Obesity is a serious health problem with side effects can vary from a complaint of disability to premature death. So decreasing in living quality is unavoidable. Some studies have proclaimed that maybe increasing rate of obesity prevalence is associated with the notable changes in the life style [11,12]. This is not a systematic research on the relationship between obesity and complication in specially people group such as T2DM patients. Meanwhile, there is no doubt that the high risk of complications can also lead to a decline in the living quality of T2DM patients [13]. However, there is no study showing the relationship between the obesity, complications and living quality in a long term follow-up. China has been experiencing the biggest shift in the world in diabetes and obesity epidemic over the past three decades [14]. Chinese Diabetes Society developed and published four editions of stand of care for type 2 diabetes management as clinical guidance for practice in China in the last twelve years. We have explored an obesity patient’s cohort with the patients in our region. So we made a survey with these data to investigate their interactive influence on T2DM patients. The aim of the survey was to evaluate the impact of obesity on the living quality and the complications risk in different body system.

Patients and Methods

We randomly selected 500 patients (the age from 45 to 65 years old; the average age is 53.25 ± 6.35; 298 male and 202 female) who were obese (30 kg/m2<BMI<34.9 kg/m2 based on WHO Guidelines approved by the Guidelines Review Committee) as obesity group, and take other 500 normal weight (18.5 kg/m2<BMI<24.9 kg/m2) patients (the age from 45 to 65 years old; the average age is 53.52 ± 6.40; 284 male and 216 female) who were paired with the obesity group (nonobesity group). There are some exclusion criteria in our cohort: 1. all the patients were first time diagnosed with diabetes in our hospital and they would be long time treatment in our hospital. 2. All patients were ability to self-care oneself without any other serious illnesses. They did not have a long-term medication history. 3. All patients were without any diabetes complication when they were diagnosed with diabetes. 4. All patients have medical insurance coving the cost. All the patients were from our diabetes patient’s database. Patients’ information was obtained when they got into our database. We would save their baseline and update their treatment history every time in our database.

In our present study, all the patients had their T2DM records in our database more than 3 years and less than 4 years for good comparability between groups. We would mark the complication state to count the incidence. “Diabetes specific quality of life” scale was used for the living quality test.

It was composed by 3 dimensions and 24 entries. Linear coring from 1-5 is made in sequence according to the options. The sum of the point of each entry is defined as total point. The higher the points are, the more serious the patient is affected, and the poorer in his living quality. Part one was physiological function, to understand the physical discomfort caused by diabetes. Part two was psychological function, to understand the impact of diabetes on patients’ mental. Part three was social relations, to understand the effects of diabetes on the patient’s interpersonal relationship and family status.

Statistical analysis

Epidata 2.1 was used to build a database. Two people typed the data in the computer individually. SPSS 13.0 statistical software was used for the analysis. The value obtained from logistic regression model was taken as the estimated value of Relative Risk (RR). P<0.05 was taken as an inspection level.

Results

First of all, the result showed there is not significantly different between the two groups expect body mass index. It proved that there was a good comparable between groups.

Secondly, the patients in non-obesity group had higher level of living quality. The T2DM patients from the different groups had similar living quality scores when they were rolled into our study cohort (Table 1). However, there was significant difference between the two groups after three or four year follow-up. The patients in Non-obesity group had better score than those in the obesity group (Table 2). In the comparison of physiology, the scores were 24.36 ± 3.28 and 22.18 ± 4.58 respectively in the obesity group and non-obesity group (t=8.65, p<0.05). In the comparison of psychology, the scores were 17.58 ± 2.89 and 15.56 ± 3.07 respectively (t=10.71, p<0.05). In the comparison of Social relation, the scores were 5.22 ± 1.28 and 4.26 ± 1.02 respectively (t=13.11, p<0.05).

  Obesity Non-obesity t/x2 value P value
Sex (Male/Female) 298/202 284/216 0.81 >0.05
Age (year) 53.25 ± 6.35 53.52 ± 6.40 0.67 >0.05
Systolic blood pressure (mmHg) 112.25 ± 6.25 112.47 ± 5.24 0.6 >0.05
Diastolic bold pressure (mmHg) 79.85 ± 10.5 78.99 ± 9.56 1.35 >0.05
Body mass index (kg/m2) 32.58 ± 2.25 22.45 ± 2.01 75.08 <0.05
Triglycerides (mmol/L) 1.89 ± 0.52 1.92 ± 0.39 1.03 >0.05
Total cholesterol (mmol/L) 5.10 ± 0.54 5.08 ± 0.68 0.52 >0.05
LDL-C (mmol/L) 2.33 ± 0.84 2.38 ± 0.72 1.01 >0.05
HDL-C (mmol/L) 1.52 ± 0.25 1.50 ± 0.19 1.42 >0.05
Fasting bold glucose (mmol/L) 9.10 ± 1.20 9.08 ± 1.17 0.27 >0.05
Uric acid (μmol/L) 270.68 ± 29.58 269.41 ± 28.14 0.7 >0.05
Creatinine (μmol/L) 87.92 ± 12.25 86.25 ± 15.74 1.87 >0.05
physiology 23.69 ± 2.23 23.41 ± 2.47 1.88 >0.05
psychology 13.47 ± 1.45 13.28 ± 1.79 1.84 >0.05
Social relation 3.01 ± 0.58 2.99 ± 0.46 0.6 >0.05

Table 1. The baseline data of patient characteristics.

  Obesity Non-obesity T value P value
Physiology 24.36 ± 3.28 22.18 ± 4.58 8.65 <0.05
Psychology 17.58 ± 2.89 15.56 ± 3.07 10.71 <0.05
Social relation 5.22 ± 1.28 4.26 ± 1.02 13.11 <0.05

Table 2. Rating scale of living quality of T2DM patients.

The patients in the obesity had higher risk in the complications. We used the epidemiological prospective study methods to work on the risk of obesity and the complications (Table 3). The results showed the patients in the obesity group have higher risk in the cerebrovascular (19.80% vs. 10.40%, t=17.23, P<0.05), peripheral artery (17.40% vs. 8.60%, t=17.12, P<0.05), cardiovascular (14.00% vs. 7.60%, t=10.63, P<0.05) and renal (9.20% vs. 5.60%, t=4.73, P<0.05) complications than that in the non-obesity group (Table 4).

  Obesity Non-obesity x2 value P value
Cerebrovascular complications 99/401 52/448 17.23 <0.05
Peripheral artery disease 87/413 43/457 17.12 <0.05
Cardiovascular complications 70/430 38/462 10.63 <0.05
Ocular complications 48/452 37/463 1.53 >0.05
Renal complications 46/454 28/472 4.73 <0.05
Peripheral neuropathy 31/469 22/478 1.61 >0.05

Table 3. The comparison of complications incidence between two groups of T2DM patients.

  Cerebrovascular complications Peripheral artery disease Cardiovascular complications Renal complications
RR 95% CI RR 95% CI RR 95% CI RR 95% CI
Obesity 5.58 3.58~9.25* 5.49 3.40~8.59* 2.25 1.29~5.43* 2.1 1.18~5.06*
Non-obesity 1.58 0.86~3.21 1.43 0.78~3.04 1.14 0.72~1.99 1.08 0.69~1.88
*P<0.05

Table 4. The estimates of obesity leading to complications incidence in terms of relative risk.

Discussion

The prevalence of obesity and T2DM are all increasing globally. The relationships between obesity and T2DM are complex, and thus difficult to elucidate [15,16]. Nevertheless, evidence supports the hypothesis that obesity increases the risks of T2DM. However, there was not a systematic research on the relationship between obesity and the T2DM complication in long follow-up time and large sample cohort. We aim to make some work in the area with our abundant medical resources.

The patients in our cohort demonstrated significant differences living quality scores between two groups. At baseline, there is no significant difference between them although the patients in the obesity group have really higher BMI than the ones in the non-obesity group. The results showed that for the patients with obesity, they would have faster decline speed in the living quality. The obesity is independently associated with lower living quality. The clinical treatment aim to the T2DM is to control the blood sugar level so that to prevent and delay the occurrence of complications, and there were a lot of evidences show that the most important factor is complication for the patients with T2DM, such as diabetic foot, ketoacidosis, diabetic nephropathy and so on [17,18]. The results showed that the incidence in the obesity group was higher than that in the non-obesity group in the comparison of cerebrovascular, peripheral artery, cardiovascular and renal complications. It is similar to a lot of studies [19,20] and it is more reliable conclusions with large sample and long-time follow-up. However, whether there was a close relationship between the obesity and complications was not known before. In our present study, it showed the patients in the obesity group have higher risk in the cerebrovascular (19.80% vs. 10.40%, t=17.23, P<0.05), peripheral artery (17.40% vs. 8.60%, t=17.12, P<0.05), cardiovascular (14.00% vs. 7.60%, t=10.63, P<0.05) and renal (9.20% vs. 5.60%, t=4.73, P<0.05) complications than that in the non-obesity group. So we can get the conclusions that (1) T2DM patients with obesity will have great possibilities poor outcome in living quality; (2) T2DM patients with obesity will have higher risk in diabetes complication.

In our research, we describe the impact of obesity on the living quality and the complications risk in different body system with long follow-up time and large sample cohort. However, there are several limitations. Firstly, the patients in our study from a single hospital registry study may limit external validity, as they reflect the experience of only our hospital. The patients have various backgrounds and treated by many different surgeons. Secondly, the distribution of patients may be skewed based on BMI. Using BMI as a measure of obesity is popular, but it has been criticized as inaccurate in certain patients, particularly those who are heavily muscled. Thirdly, there was something in contrast with other reported papers. Our study showed there is no significantly different between the two groups in the risk of Peripheral neuropathy and Ocular complications. The reason maybe has some relationship with the distance of fellow-up. As some reported pagers, the Peripheral neuropathy and Ocular complications will focus on more than three years later [21,22]. We will continue our work on those problems in the future research with more time fellow-up.

References