Betsy Corina Sosa-García,1 Cleotilde García-Reza,2 Vicenta Gómez-Martínez,2 María de Lourdes Basurto-Acevedo,3 Rigoberto Oros-Pantoja,4 Alma Grisel Díaz-Martínez3
1,2,4Universidad Autónoma del Estado de México. Toluca, Estado de México, México. 3Instituto Mexicano del Seguro Social, Unidad de Investigación Médica en Enfermedades Endocrinas, Ciudad de México, México
1Laboratorio de Neuroquímica, 2Facultad de Enfermería, 4Departamento de Neurociencias
Correspondence: Cleotilde García-Reza
Received: April 13th 2016
Judged: July 8th 2016
Accepted: October 14th 2016
Introduction: In the last decades, type 2 diabetes mellitus (T2DM) has increased considerably in Mexico. In 2000 the National Health Survey reported 2.1 millions of people affected; in 2006, 3.7 millions; and in 2012, 6.4 millions. Acting together, T2DM and cardiovascular disease are the leading cause of mortality with a trend that is increasing progressively in recent years.
Objective: To identify and describe metabolic and non-metabolic risk factors in adults enrolled in a health center in the Estado de México.
Methods: A non-random sampling of 586 male and female patients was divided into three groups: normal glucose (NG), impaired fasting glucose (IFG) and T2DM. Metabolic (triglycerides, HDL-cholesterol, LDL-cholesterol, as well as systolic and diastolic blood pressure) and non-metabolic (weight, height and waist circumference) variables were measured.
Results: Mean levels of total cholesterol in the three groups were higher in the GN group with 203.6 ± 36.7 mg/dL vs. 199.4 ± 39.7mg/dL vs. 200.6 ± 44.7mg/dL, respectively. Serum levels of LDL-cholesterol in the GN and GAA groups were similar with 120.7 ± 32.3 vs. 120.5 ± 33.7, respectively; in the T2DM group, the serum level of LDL-C decreased (114.6 ± 36.5 mg/dL).
Conclusions: Our findings show that patients with T2DM along with patients without diabetes show high frequency of alterations in lipid profiles and diastolic blood pressure, as well as abdominal obesity.
Keywords: Diabetes mellitus; Risk factors; Nutritional physiological phenomena; Chronic disease
The American Diabetes Association (ADA) notes that type 2 diabetes mellitus (DM2) is a metabolic disease characterized by the presence of hyperglycemia. One-third of patients with DM2 increase their risk of developing cardiovascular disease two to four times.1-5 More women than men suffer from this epidemic, especially in developed countries. China, India, and the United States are the countries with the largest number of people with diabetes.6
The World Health Organization (2014) reports that worldwide the number of people with DM2 increased from 30 million in 1995 to 366 million in 2011; and estimates that by 2030; there will be 592 million people who will have altered glucose when fasting.5-10
On the other hand, a study carried out in nine Latin American countries demonstrated that glycemic control is poor,3-5 the reason why diabetes is a public health problem. The magnitude of the problem means that every six seconds a person dies from diabetes mellitus and there are 5.1 million deaths per year. The impact on economic, social, and quality of life terms makes this problem a global priority.11-15
It has recently been determined that the risk of cardiovascular disease is 11 times higher in the diabetic population than in the population without diabetes.13-18 To this regard, almost 500 million people in the world are obese, a figure that corresponds to 12% of the world population. At the same time, the 26% of the adult population with the highest degree of obesity has been identified as from the American continent, and the lowest degree in Southeast Asia, with 3%. This suggests an existing risk of cardiovascular disease.19,20
The term impaired fasting glucose (IFG), dysglycemia, or prediabetes is applied to those clinical cases with glucose levels above normal values but below the levels considered for DM2. Given its high frequency, it is convenient to consider prediabetes as a high risk for developing diabetes and vascular complications.4-7 The modification or alteration of these variables can occur in people with normal glucose, IFG and DM2. As such, DM2 and cardiovascular disease are two diseases of high morbidity and mortality, results of the metabolic syndrome.7,21-23
In the last decades, DM2 has had a notable increase in Mexico. In 2000, the Encuesta Nacional de Salud (ENSA) reported 2.1 million people affected (4.6%); in 2006, 3.7 million (7.3%); and 6.4 million (9.2%) in 2012.16-18 Regarding incidence of DM2 in Mexico, in 1995, it ranked ninth; and seventh in 2011; and it is possible that it will occupy the sixth place by the year 2030. Currently, along with cardiovascular disease, it is the leading cause of mortality with a progressive upward trend in recent years.17-18
The importance of an early and timely diagnosis helps people to reach a life expectancy greater than estimated, have a decent quality of life, as well as to reduce higher expenditures in the health sector.21
The purpose of the present study was to identify and describe the metabolic and non-metabolic risk factors in adults enrolled in a health center in the Estado de México.
The groups conformed to the following criteria:
Descriptive and transversal study, derived from a research project of the Instituto Nacional de Ciencias Médicas y Nutrición. In March and August 2014, 586 people, of both sexes, between 30 and 70 years of age enrolled in a health center in the Estado de México. From a non-probabilistic sampling, three groups were formed based on the following criteria: Group 1 included people with normal glucose (NG) levels, between 70 and 99 mg/dL; Group 2, people with altered fasting glucose (IFG), between 100 and 125 mg/dL; and Group 3, people with type 2 diabetes mellitus (DM2); a BMI≥23 kg/m2; and treatment with oral hypoglycemic agents, insulin, or both.
Other criteria were also considered to include participants, such as the presence of fever (>38°C); having been in bed for more than 48 hours in the two weeks prior to enrollment; suffering from coronary artery disease (CAD); or risk equivalent of congenital heart disease (CHD); active liver disease or presented during the previous six months; significant renal dysfunction, including serum creatinine>1.7 mg, above the ULN or nephrotic syndrome; history of neoplasia; current abuse or dependence on alcoholic beverages or drugs; as well as suffering from depression or uncontrolled psychosis.
People under 30 years of age with DM1 or gestational diabetes, a body mass index (BMI)<23 kg/m2, incomplete data on anthropometry, lipid profile, or glucose levels were excluded.
For the clinical evaluation of the people participating in the study, a questionnaire was applied and weight, height, blood pressure, waist circumference, and fasting blood sample were measured. The day before the sampling date, researchers contacted the head of the health center to confirm the attendance of the participants and remind them to fast.
Body weight (kg) and height (m) were measured based on the recommendations of Norma Oficial Mexicana NOM-043-SSA2-2005, Servicios básicos de salud. Promoción y educación para la salud en materia alimentaria. Criterios para brindar orientación.24 With these measurements, each participant's BMI was calculated. Waist circumference was measured at the level of the greater trochanters and hip circumference at the level of the gluteal zone at maximum extension of the buttocks posteriorly.25 A mercury sphygmomanometer was used to measure blood pressure with the person at rest in a seated position. This measurement was performed at three moments to obtain the average systolic and diastolic pressures.
The basal glucose test was performed after 12 hours of fasting. The criteria for diagnosis of glucose were, according to the ADA,1 considered controled when the person had a fasting glucose level between 70 and 129 mg/dL, and poor control when there was a glucose level>130 mg/dL.
Biochemical tests included glycemic assessment, lipid profile including triglycerides, total cholesterol, and HDL-cholesterol. LDL cholesterol was calculated using the Friedewald formula.26 The alteration of metabolic and non-metabolic variables was studied based on the criteria of the Third Report of the Expert Panel on Detection, Evaluation and Treatment of Adult Hypercholesterolemia of the Program National Cholesterol Education Institute, also known as NCEP-III: impaired fasting glucose (≥100 mg/dL); dyslipidemia (triglycerides≥150 mg/dL, HDL<50 mg/dL in women and<40 mg/dL in men); arterial hypertension (≥130/85 mm Hg); obesity (waist circumference≥80 cm in women and≥90 cm in men).27,28
For statistical analysis, a database was constructed with the statistical package SPSS, version 21. The results were analyzed by means of descriptive statistics of arithmetic mean and standard deviation (SD), in order to determine the significant differences. Bonferroni test was used to determine statistical significance, with a confidence level of 95% (p<0.05), and a multivariate regression analysis of variances (ANOVA) to determine the description of non-metabolic variables (weight, height, waist circumference) and metabolic variables (triglycerides, HDL-C, LDL-C, systolic and diastolic blood pressure) in the three study groups.
Of the 586 participants, 172 (29%) were diagnosed with normal glucose, 59 (10%) with altered glucose, and 355 (61%) with DM2.
The group of participants with normal glucose consisted of 49 men (29%) and 123 women (71%). Those with impaired glucose consisted of 38 men (64%), and 21 women (36%). The group of patients with DM2 were 123 men (35%) and 232 women (65%). The mean age for the NG group was 50.9 years (30-70); the IFG group was 52.0 years (33-69); and for the DM2 group, 56.0 years (35-70). Among the participants, the average socioeconomic stratum prevailed: 30% belonged to the NG group; 38% to the IFG group; and 32% to the DM2 group. The education level was secondary education or a technical career in 27.9% of the NG group; 33.9% of the IFG group; and 27.0% of the DM2 group.
Mean weight was similar in the normal glucose and altered glucose groups with 73.3±13.0 kg. This value was higher when comparing the data with the DM2 group (70.4±14.7 kg), but there was no significant difference between the groups.
According to the mean BMI values, it is evident that the three study groups present values above the established limit, however, there was no significant difference when associated with the groups (NG 28.4±5.0; IFG 28.2±4.4; and DM2 27.9±4.7).
The waist circumference figure was similar for in all three groups. Most participants had one or more components of the metabolic syndrome. Central obesity was present in both women and men with a value of p=0.554 (Table I).
|Table I. Comparison of non-metabolic variables in three groups according to figures on adult normal glucose, impaired fasting glucose, and DM2 (
|a vs. b||a vs. c||b vs. c|
|Source: Our own elaboration with data from the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zúbiran (INCMNSZ)
NGa=normal glucose; IFGb=impaired fasting glucose; DM2c=type 2 diabetes mellitus; SD=standard deviation; BMI=body mass index
a vs. B=normal glucose vs altered glucose; a vs. C=normal glucose vs DM2; b vs. C=glucose vs against DM2
p was statistical significant p≤0.05.The comparison was made with ANOVA and post hoc analysis for the Bonferroni method was used.
When comparing the metabolic variables among the three groups (NG, IFG, DM2), it is unquestionable that mean total cholesterol levels were higher in the normal glucose group (203.6±36.7 mg/dL; 199.4±39.7 mg/dL; and 200.6±44.7 mg/dL, respectively).
Both the NG and IFG groups had similar serum LDL-C levels (120.7±32.3 vs 120.5±33.7); However, the group of participants with DM2 had a decrease in serum LDL-C levels (114.6±36.5 mg/dL). These data place the study population at risk for developing metabolic complications related to diabetes.
The triglyceride concentration and systolic blood pressure (149.5±23.9 mm Hg), were slightly higher in the DM2 group,. Also, the association between high cholesterol and blood pressure was statistically significant, with a Pearson correlation of p<0.0001 (Table II).
|Table II. Comparison of metabolic variables in three study groups according to figures on normal glucose, impaired fasting glucose, and type 2 diabetes
|a vs. b||a vs. c||b vs. c|
|Total Cholesterol (mg/dL)||203.6±36.7||199.4±39.7||200.6±44.7||1.000||1.000||1.000|
|Source: Our own elaboration with INCMNSZ data
NGa=normal glucose; IFGb=impaired fasting glucose; DM2c=type 2 diabetes mellitus)
a vs. v=normal glucose vs. altered glucose; a vs. c=normal glucose vs. DM2; b vs. c=altered glucose vs. DM2
HDL-C=high-density lipoprotein; LDL-C=low density lipoprotein (figure analyzed with triglycerides<400 mg/dL); SBP=systolic blood pressure; DBP=diastolic blood pressure
*Statistical significance was obtained (≤0.05). The comparison was made with ANOVA and post hoc analysis for the Bonferroni method was used.
Of the total number of participants studied, the DM2 group presented a higher frequency of cardiometabolic risk factors. However, an increase in metabolic risk factors, such as abdominal obesity, elevated LDL-C, and hypertriglyceridemia, was identified in the NG and IFG groups; that is to say, this is population with a high cardiovascular risk.9-19
Alterations present in the NG and IFG groups, such as abdominal obesity, arterial hypertension, and dyslipidemia, suggest presence of insulin resistance in this non-diabetic population, a probable endothelial dysfunction and fibrinolysis involvement. All these elements are part of the transition period from prediabetes to diabetes.29
The proportion of men and women with DM2 in this study exceeds the general figure reported by ENSANUT in 2016 (9.6%).21 On the other hand, it coincides with that described by Franzini and Soriguer.30,31 Although the sample in the present study is not representative of the national population, there are possible explanations regarding type of diet, sedentarism, and biological sustenance.32 With the present data (taking into account the context in which they were obtained), efforts should be directed towards generating effective prevention strategies as a cornerstone to delay the presentation of diabetes or chronic complications.33-36
Achieving glucose control is a major challenge for health services and for people with diabetes mellitus.18 The challenge is and will be increasing as the global prevalence of diabetes increases, given that it was 6.4% of people aged 20 to 79 years in 2010, and will increase to 7.7% by 2030. These estimates correspond to a 69% increase in adults with diabetes developing countries and in developed countries, this increase is 20% for the same population.6
On the other hand, it is accepted that adequate glycemic control has a close relationship with the probability of suffering complications.33,34 The timely diagnosis of glucose intolerance can delay the onset of microvascular complications and decrease the progression of diabetes. It is known that molecular effects associated with insulin resistance in the endothelial cell lead to a proinflammatory and prothrombotic state, which would explain the increase in cardiovascular risk.31
Cholesterol levels did not show significant variations among the groups in this study. However, they indicate that they are not a fundamental element of the lipid profile with a higher atherogenic risk, which coincides with that reported in several published studies.3-13
Similarly, hypertriglyceridemia and decreased HDL-C are similar in the different groups of both normal and altered glycemia. Lipid alterations, such as those observed in LDL-C, suggest alteration of fat fraction by small, dense particles of high atherogenic power, called phenotype B.32 The HDL-C and LDL-C fractions are associated with an increased risk of stroke of up to two times, and triple the risk of coronary heart disease and cardiovascular mortality.36
In diabetes mellitus, there is a situation of accelerated atherogenesis, which is associated not only with hyperglycemia, but also with other risk factors, such as dyslipidemia, hypertension, hyperinsulinemia/insulin resistance, and coagulation alterations, among others.33
With the results of this study, it is opportune to notice elevation in BMI and waist circumference as a potential component of metabolic syndrome, even in non-diabetic patients. According to WHO, obesity is estimated to occur in 12% of the world's population, with large contrasts ranging from the highest level in America to the lowest in Southeast Asia. This is determinant for the population to be at risk of developing diabetes, cancer, and cardiovascular problems. In addition, the presence of intra-abdominal fat, increased lipolytic activity, and increased fatty acids have a further impact on liver function.36 Després states that the simultaneous presence of abdominal perimeter and triglyceride levels≥180 mg/dL in men is associated with a 3.5-fold increased risk for cardiovascular events.37
The number of participants recruited in this study, mostly carriers of type 2 diabetes mellitus, are not a strict representation of the Mexican population. However, with the results obtained an estimate of what is happening in our country can be made.
Another limitation is that glucose tolerance curve was not performed in non-diabetic individuals, which would have allowed the identification of people with postprandial alteration of glucose, an entity that is currently considered within the prediabetes category and therefore these people are considered an at-risk population.
It is suggested to continue with future research, using indices to determine insulin resistance and other markers, in the field of prevention.
In this study, a high frequency of other metabolic risk factors was identified in the DM2 group. However, in the groups with normal glucose and with fasting glucose alteration, components of metabolic syndrome, such as abdominal obesity and hypertriglyceridemia, presented.
Timely identification of metabolic alterations is the main tool to predict cardiovascular disease. The latter is a cause of high morbidity and mortality in the Mexican population.
Another condition that should be emphasized regarding the study population is glycemic control, effective in reducing the potential risk of complications from diabetes mellitus.
The questioning process on this public health issue is impressive, as hyperglycemia is considered a global epidemic due to its high occurrence and its presentation at earlier ages. This health problem is becoming more frequent and is accentuated by the prevalence of obesity. The problem represents a great challenge, but there is also a range of possibilities to offer prevention programs under the perspective of continuous and ongoing monitoring. The results of this work underscore the importance of the glucose level, which is a powerful predictor of cardiovascular risk.
Thanks to the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zúbiran, for the support received to carry out this study.