Lipid profile, random blood glucose and carotid arteries thickness in human male subjects with different ages and body mass indexes

Abstract

Objective

This article investigated the effect of age and body mass index of male humans on the carotid arteries intima media thickness (IMT) and the blood concentration of glucose, triglycerides, total cholesterol and HDL cholesterol.

Methods

Thirty seven normal male human subjects participated in this study. The participants were classified to three groups depending on their age; 20–29 (11), 30–39 (14) and 40–49 (12). Also, the study subjects were divided to three groups according to their body mass index; normal (13), overweight (13) and obese (11). The Anova test was used for the statistical analysis of the obtained results.

Results

The body mass index significantly affected the blood glucose concentration while its effect on all the other parameters was insignificant. The age significantly affected all the studied parameters except the blood glucose, triglycerides and HDL cholesterol. The total cholesterol/HDL ratio was significantly affected by the age and insignificantly by the body mass index.

Conclusions

The age was more effective on the studied parameters than the body mass index. Worsening of the lipid profile was seen in the overweight participants rather than the obese ones.

Keywords:

• Triglycerides
• total cholesterol
• HDL
• total cholesterol/HDL ratio
• IMT

Introduction

Normal male aging is associated with symptoms such as the loss of hearing, visual acuity, vestibular function, muscle weakness, osteoporosis, osteoarthritis, urologic and immune system changes, low blood testosterone concentration, and sextual inactivity. Most of the agining related symptoms are due to age associated comorbidities such as the metabolic syndrome, dyslipidemia, obesity, diabetes, cardiovascular diseases, and hypertension [1–5]. Aging is chacterized by inflammation and high blood cytokines possibly because of the low blood testosterone. Some studies stated that the testosterone anti-inflammation activity [6].

Obesity is classified to three categories depending on the body mass index (BMI): (i) obesity class I (BMI: 30–34.9), (ii) obesity class II (BMI: 35–39.9), and (iii) obesity class III (BMI ≥ 40). The underweight, normal, and the overweight (pre obesity) groups are (˂18.5), (18.5–24.9), and (25–29.5), respectively [7]. BMI (obesity indicator) is considered as a risk factor for diabetes, cardiovascular diseases, hypertension, some cancers, and premature death. It is reported by many studies that the overweight and obese individuals are at high risk of developing caradiovascular diseases [8–10]. Phramceuticals and their effects on body weight is considered as strong obesity affecting factor such as the endocrine disrupting chemicals and the endocrine therapy [10,11]. There is strong association between aging, low blood concentration of testosterone and obesity. Some studies proved that the low blood concentration of testosterone is obesity inducing factor and testosterone therapy induces body weight gain and improves and the Aging Males’ Symptoms (AMS) [12–14].

Functionally, lipids are very important for human health and for the prevention of non-communicable diseases like the obesity, depression, heart diseases, Parkinson and Alzheimer. Functional lipids include the unsaturated fatty acids, medium chain triglycerides and phytosterols [15]. Dyslipidemia is the blood lipid profile abnormalities such as elevated total cholesterol, LDL cholesterol, and triglycerides and decreased HDL cholesterol [16]. Dyslipidemia is one of the metabolic syndrome symptoms as well as the insulin resistance, abdominal obesity, chronic stress, and high blood pressure. The dyslipidemia and metabolic syndrome are age comorbidity factors and they are risk factors for diabetes milletus type 2, cardiovascular diseases, cancer, and mortality. From the reviewed literature, there is causative interrelationship between the comorbidity factors of Aging [17–20]. Furthermore, it is reported that morbidly obesity is associated with high concentration of blood uric acid [21].

Blood glucose level is affected by the diet type and amount, psychological or physical stress due to the effect of stress hormones, dehydration, aging, uric acid to HDL ratio, during menstrual period because of the hormonal changes, hypoinsulinemia in Diabetes, and as side effect of steroids such testosterone and antipsychotic medications [22–24]. Random blood glucose concentration (≥100 mg/dl) is considered as one of the diabetes mellitus screening tests by the International Diabetes Federation and it should be confirmed by glucose tolerance test [25]. It was mentioned that the random blood glucose (≥100 mg/dl) is strongly associated with undiagnosed diabetes and it should be introduced as screening test for diabetes [26]. However, the diabetes mellitus is mostly accompanied by abnormal lipid metabolism like the primary hyper lipoproteinemia and hypertriglyceridemia [27].

Carotid arteries are the major vessels that carry the blood to the brain. There are two carotid arteries located on the left and right side of the neck. The two carotid arteries are divided to internal and external carotid arteries. The internal carotid arteries are responsible for supplying the brain by oxygenated blood while the external arteries supply the neck, face and scalp. The normal thickness of the common carotid arteries intima media is ranging from 0.4 mm to 1 mm. Carotid artery disease is characterized by accumulation of plaques on the inner side of the arteries leading to low blood supply to the brain and stroke. Risk factors of carotid artery disease include diabetes, high blood pressure, metabolic syndrome, overweight or obesity, smoking, unhealthy diet, lack of physical activity, family history of atherosclerosis, blood concentration of testosterone, mean platelet volume, and older age [28–33].

This study investigated the effect of age and body mass index on the lipid profile, random blood glucose and the common carotid arteries intima media thickness. The investigated lipid profile contained the total cholesterol, HDL cholesterol and triglycerides.

Material and methods

Study design

This study can be classified as descriptive, crossectional, and case control research.

Study community, sample collection and treatment

Thirty seven physically healthy human subjects living in Asir region (south western part of Saudi Arabia) participated in this study. Five milliliters of intravenous blood sample was obtained from each study subject. The blood five milliliters were divided into fluoride tube (for blood glucose) and EDTA tube (for lipid profile).

Ethical clearance

This study was implemented after it was ethically approved (REC# 2018-06-36) from the research ethics committee, College of medicine, King Khalid University, Saudi Arabia. The study participants were involved after an oral informed consent was obtained.

Analysis procedure

The random glucose and the lipid profile was determined using the spectrophotometer and the analysis kits of HUMAN, Germany. The kit code numbers of the total cholesterol, HDL cholesterol and triglycerides were 10,017, 10,084 and 10,720 P, respectively.

Measurement of intima media thickness of the common carotid arteries

Real time gray scale ultrasound was performed to measure intima media thickness (IMT) for both carotid arteries by using logic 3, LSD 30269WS5, General electric ultrasound machine. High frequency (10MHZ) linear transducer was used to give good image quality. No need to prepare the participants for the examination. The exam began with the subject supine. Then the participants were asked to elevate their head and rotate it to the investigation side. The longitudinal dimensions of the Right and left (IMT) for carotid arteries were measured. The measurement was taken from the posterior wall of the carotid arteries after magnifying the image for better visualization. Thermal papers were used to record the selected images.

Statistical analysis

The SPSS version 20 was used for the analysis of the obtained results. The independent samples t-test was used to compare the results of the patients and the healthy subjects while the ANOVA least significance difference (LSD) post hoc test was used to investigate the effect of body mass index and age on the studied parameters in the patients and controls (healthy subjects).

Results

Description of the study population

The age of the study community was divided to three groups (20–29), (30–39) and (40–49). The number of the participants in the three age groups were 11, 14 and 12, respectively. According to the body mass index (BMI), the participants were categorized in three groups; normal weight (BM = 18.5–24.9), overweight (BMI = 25–29.9) and obese (BMI ≥ 30). The participants with normal weight, overweight and obese were 13, 13 and 11, respectively.

Effect of age and Body Mass Index (BMI) on the studied parameters

The mean values, standard deviations and the ranges of the carotid arteries thickness, blood glucose, lipid profile parameters and cholesterol ratios in the participants with different age groups and BMI are presented in Tables 1 and 2. However, the aging significantly increased the carotid arteries thickness, total cholesterol concentration and the total cholesterol/HDL ratio (Table 1). The BMI significantly affected the blood glucose concentration and insignificantly affected the other parameters (Table 2). From the BMI results, It was clear that bad lipid profile was associated with the overweight participants rather than the obese. The overweight participants had the highest mean of total cholesterol, triglycerides, cholesterol\HDL ratio and IMT thickness of the left carotid artery. The overweight participants were more susceptible to bad lipid profile and atherosclerosis.

Table 1. The mean values, standard deviations and ranges of the studied parameters in the three age groups.

	Mean	Std. deviation	Minimum	Maximum
Glucose mg\dl
20–29	96.38	10.64	74.00	107.00
30–39	124.36	57.16	81.00	287.00
40–49	118.18	34.19	80.00	177.00
Total	115.52	42.96	74.00	287.00
Total cholesterol mg\dl
20–29	124.71	25.88	95.90	177.30
30–39	157.97	42.51	114.70	281.40
40–49	170.76	29.35	125.50	204.30
Total	154.05	38.16	95.90	281.40
Triglycerides mg\dl
20–29	126.65	106.42	32.50	344.20
30–39	276.35	279.91	84.00	1118.40
40–49	227.03	94.41	91.00	400.00
Total	221.97	198.38	32.50	1118.40
HDL mg\dl
20–29	47.24	17.34	31.20	84.70
30–39	46.44	17.17	24.40	88.80
40–49	39.15	14.27	22.00	67.00
Total	44.13	16.16	22.00	88.80
Total Cholesterol\HDL
20–29	2.80	0.67	1.60	3.50
30–39	3.62	0.96	2.10	6.09
40–49	4.73	1.54	2.90	8.50
Total	3.79	1.34	1.60	8.50
IMT of the right carotid artery (mm)
20–29	0.51	0.064	0.40	0.60
30–39	0.51	0.24	0.00	0.80
40–49	0.74	0.19	0.50	1.20
Total	0.58	0.22	0.00	1.20
IMT of the left carotid artery (mm)
20–29	0.51	0.064	0.40	0.60
30–39	0.61	0.12	0.40	0.80
40–49	0.73	0.13	0.60	1.00
Total	0.62	0.134	0.40	1.00

The highest age group (40–49) was characterized by the highest mean value of the total cholesterol, total cholesterol/HDL ratio and IMT of the two common carotid arteries. IMT: intima media thickness.

Table 2. Effect of body mass index on the studied parameters.

	Mean	Std. deviation	Minimum	Maximum
Glucose
Normal	103.9	25.74	74	172
Over weight	107.9	27.16	80	160
Obese	140.5	61.54	87	287
Total	117.2	43.59	74	287
Total cholesterol
Normal	142.2	33.61	95.9	202.5
Over weight	173.1	50.31	107.9	281.4
Obese	156.1	28.13	112.8	194
Total	155.6	38.31	95.9	281.4
Triglycerides
Normal	163.9	108.67	32.5	400
Over weight	319.9	329.16	60	1118.4
Obese	238.5	133.57	85.8	530
Total	233.4	204.83	32.5	1118.4
HDL
Normal	41.1	7.92	27.1	58.2
Over weight	45.7	21.97	22	88.8
Obese	48.3	16.94	30.1	84.7
Total	44.9	15.78	22	88.8
Total Cholesterol\HDL
Normal	3.6	1.12	1.6	6.25
Over weight	4.4	1.85	2.5	8.5
Obese	3.5	0.87	2.1	4.7
Total	3.8	1.31	1.6	8.5
IMT of the right carotid artery
Normal	0.58	0.19	0.4	1.2
Over weight	0.58	0.22	0.0	0.8
Obese	0.58	0.24	0.0	0.8
Total	0.58	0.21	0.0	1.2
IMT of the left carotid artery
Normal	0.58	0.14	0.4	1.0
Over weight	0.66	0.08	0.6	0.8
Obese	0.64	0.15	0.4	0.8
Total	0.62	0.13	0.4	1.0

Worsening of the lipid profile was seen in the overweight participants rather than the obese ones. Overweight participants were characterized by the highest mean of total cholesterol, triglycerides, total cholesterol/HDL ratio and IMT of the left carotid artery. IMT: intima media thickness.

The age was significantly correlated to the total cholesterol, total cholesterol/HDL ratio and IMT of the right and left carotid arteries while the body mass index was significantly correlated to the blood glucose only. The IMT of the left carotid artery was significantly correlated to the blood glucose, total cholesterol and thickness of the right carotid artery. The lipids were significantly correlated to each other’s and to the total cholesterol/HDL ratio (Table 3).

Table 3. Significant Pearson correlations.

Correlated parameters	Pearson correlation	Significance
Age versus cholesterol	0.47	0.006
Age versus total cholesterol\HDL ratio	0.53	0.001
Age versus the IMT of the right carotid artery	0.38	0.027
Age versus the IMT of the left carotid artery	0.56	0.001
BMI versus Blood glucose	0.36	0.042
Glucose versus the IMT of the left carotid artery	0.50	0.005
Total cholesterol versus triglycerides	0.68	≤0.001
Total cholesterol versus HDL	0.50	0.003
Total cholesterol versus the IMT of the left carotid artery	0.36	0.05
HDL versus triglycerides	0.44	0.011
HDL versus total cholesterol\ HDL ratio	−0.65	≤0.001
The IMT of the right carotid artery versus the IMT of the left carotid artery	0.96	≤0.001

Discussion

Regarding the effect of age on the blood glucose concentration, it was previously reported that aging was accompanied by significant increase in the fasting and random blood glucose [34–36].

A lot of debates were reported regarding the correlation of aging and the concentration of triglycerides and total cholesterol and decrease in the HDL concentration. Mahroum research group stated that both LDL cholesterol and total cholesterol decrease with the increase of age above 55 years in Sudanese patients [37]. This study reported that the age significantly increased the concentration of the total cholesterol. A Japanese study mentioned that total and LDL cholesterol concentration increase with aging while the HDL cholesterol concentration remain at a constant level after puberty [38]. However, we have reported increased total cholesterol during age increasing and decreased HDL cholesterol with aging. Rural population in Edo state of Nigeria showed that there were positive correlations between age and total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides [39]. A study in Poland individuals found that worsening of blood lipid profile is a character of aging [40]. Azab (2013), studied the astherosclerosis in patients with lower urinary tract function and reported that the astherosclerosis is associated with significantly high blood triglycerides and low HDL – Cholesterol irrespective of the age [41].

All the contacted literature reported that the age induces the thickening of the carotid arteries intima media. The research group of Munckhof concluded that the thickening of the carotid, lower and upper limb arteries are age related [42]. Other studies stated that carotid arteries wall thickening in healthy subjects increases with age increase [43,44]. Wang et al. found that shortening of leukocytes telomers is associated with increased carotid artery stenosis [45]. However, aging is well known to be accompanied by telomere shortening [46].

Concerning the effect of body mass index on the blood glucose level (fasting or random), it was reported that there was a positive effect of the BMI on the blood glucose [47–49].

The previous researches that studied the effect of body mass index on the lipid profile of human individuals showed that there were different types of effects depending on the ethnicity, geographical area, physical activity and age. A study conducted in Cleveland clinic in Florida state concluded that high body mass index was directly related to the concentration of the triglycerides, inversely related to the HDL cholesterol [50]. Orenes-Piñero et al., stated that there was a significant relation between the HDL cholesterol and the BMI classes [51]. Jaceldo-Siegl et al., concluded that the total cholesterol/HDL cholesterol and the LDL/HDL ratios were significantly lower in the people with BMI less than 25 compared to those with BMI more than 25 [52]. Our results showed that there was insignificant variations between the normal, overweight and obese individuals with regard to their total cholesterol/HDL ratio. However, the highest cholesterol/HDL ratio were seen in the overweight individuals rather than the normal or the obese ones. Similar to the findings of this study Begum et al., concluded that there were no significant correlations between the BMI and all the lipid profile parameters [53]. Pinto and Power, mentioned that BMI increase leaded to increased non HDL cholesterol while lowering the BMI by one unit decreased the non HDL cholesterol by 1.5% [54].

It is known that the body mass index had variable effects on the thickness of the carotid arteries. Most of the previous studies found that the body mass index significantly increased the intima media thickness of the carotid arteries [55,56]. Stevens et al., found that the body mass index was not associated with carotid arteries thickness if other thickening factors were adjusted like the ethnic group, age and gender [57]. Kawada et al., studied the effect of aging, metabolic syndrome componenets, and C-reactive protein on the intima media thickness of the carotid arteries and concluded that the aging, number of metabolic syndrome components and C-reactive protein are indicators of the carotid arteries intima media thickness [31]. Kwon et al., reported that the carotid arteries intima media thickness in aging males is induced by the metabolic syndrome and the low blood concentration of testosterone [32].

Limitations of the study

As this is a descriptive research, it suffers from the small number of samples and subgroups and its’ conclusions cannot be generalized.

Conclusions

In human males living at Asir region, The age positively and significantly affected the carotid arteries thickness, total cholesterol concentration and the ratio of total cholesterol/HDL and it was significantly correlated to total cholesterol, total cholesterol/HDL ratio and the IMT of the right and left carotid arteries. The BMI significantly increased the random blood glucose and insignificantly affected the lipid profile, total cholesterol/HDL ratio and the IMT of the carotid arteries and it was significantly associated with increased blood glucose. The overweight individuals were characterized by bad lipid profile compared to the obese and normal weight individuals. Special clinical attention should be drawn to the overweight individuals since they are susceptible to atherosclerosis.

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

The authors are very thankful to the deanship of scientific research at King Khalid University for supporting this project under grant number R.G.P1.\92\40.