Expression level of myocardial enzymes in patients with schizophrenia: Predictive value in the occurrence of violence

Abstract

BACKGROUND

Schizophrenic patients are prone to violence, frequent recurrence, and difficult to predict. Emotional and behavioral abnormalities during the onset of the disease, resulting in active myocardial enzyme spectrum.

AIM

To explored the expression level of myocardial enzymes in patients with schizophrenia and its predictive value in the occurrence of violence.

METHODS

A total of 288 patients with schizophrenia in our hospital from February 2023 to January 2024 were selected as the research object, and 100 healthy people were selected as the control group. Participants’ information, clinical data, and laboratory examination data were collected. According to Modified Overt Aggression Scale score, patients were further divided into the violent (123 cases) and non-violent group (165 cases).

RESULTS

The comparative analysis revealed significant differences in serum myocardial enzyme levels between patients with schizophrenia and healthy individuals. In the schizophrenia group, the violent and non-violent groups also exhibited different levels of serum myocardial enzymes. The levels of myocardial enzymes in the non-violent group were lower than those in the violent group, and the patients in the latter also displayed aggressive behavior in the past.

CONCLUSION

Previous aggressive behavior and the level of myocardial enzymes are of great significance for the diagnosis and prognosis analysis of violent behavior in patients with schizophrenia. By detecting changes in these indicators, we can gain a more comprehensive understanding of a patient’s condition and treatment.

Key Words: Schizophrenia; Myocardial enzyme index; Act of violence; Predict; Violence prediction; Aggressive behavior; Clinical data analysis; Biochemical markers

Core Tip: This study analyzes the expression levels of myocardial enzymes in patients with schizophrenia and explores their predictive value for violent behavior. The study involved 288 cases. The study was reviewed and approved by the Shaoxing Seventh Hospital Medical Ethics Committee. Patients with schizophrenia and 100 healthy controls, and patients were divided into violent and non-violent groups based on Modified Overt Aggression Scale scores. The results showed that there was a significant difference in serum myocardial enzyme levels between patients with schizophrenia and healthy individuals, and the myocardial enzyme levels in the violent group were higher than those in the non-violent group. Previous aggressive behavior and myocardial enzyme levels are of great value for diagnosis and prognosis analysis. By monitoring these indicators, we can have a more comprehensive understanding of the patient's condition and treatment progress, providing important references for clinical management.

INTRODUCTION

As a common mental illness, schizophrenia will not only change the patient’s way of thinking and inner emotions in clinic, but also their will and behavior to a certain extent. Such changes may recur frequently, which is a serious mental disorder[1]. Among these, the most typical behavior of patients with schizophrenia is violence[2]. Compared to the healthy population, people with schizophrenia are more prone to violence. On the one hand, because the symptom is extremely difficult to find, and explosive and destructive, it has a certain degree of negative impact on medical staff, patients, and community residents. However, the number of violent acts is increasing annually. Therefore, distinguishing and judging violent acts in time and effectively, and even predicting when violent acts occur, is of great clinical value. Some scholars have suggested that because of their low level of cognition and being controlled by negative emotions and even psychotic symptoms, patients are angry and impulsive, which leads to violent behavior[3]. Patients in the onset stage will not only have emotional instability but also have abnormal behavior operations. Clinical testing and blood analysis has revealed that the activity of myocardial zymogram in patients’ serum has been significantly improved, especially when patients are excited and excited, and myocardial zymogram is even more abnormally increased. No relevant evidence of heart disease has been found for the time being.

MATERIALS AND METHODS

Study population and data collection

A total of 288 patients with schizophrenia admitted to our hospital from February 2023 to January 2024 were selected as the research object of the case group, and 100 healthy people were selected as the control group. The case group comprised 72 males and 88 females aged 22–59 years, with an average age of 43 years ± 6.23 years.

Based on the Modified Overt Aggression Scale (MOAS) score, the case group was further divided into violent (123 cases) and non-violent (165 cases) groups. Among them, the violent and non-violent groups included 30 males and 38 females and 42 males and 50 females, respectively, aged from 21 years to 61 years, with an average of 44 years ± 6.57 years.

Inclusion criteria: (1) The subjects met the diagnostic criteria of schizophrenia or acute schizophrenia-like psychotic disorder in the classification of mental and behavioral disorders in the International Classification of Diseases-10[4]; (2) The subjects were 20-65 years old, regardless of sex; (3) The patients and their families were informed about this study and signed the consent form; (4) The selected patients did not take any antipsychotic drugs for at least two weeks before the study, and had not received electroconvulsive therapy; (5) Both groups were patients with acute episode of schizophrenia; and (6) In the violent group, a history of violent aggression, and definite aggression one week before admission, and the revised MOAS score was ≥ 5[5]. The non-violent group has no violent behavior in the past and now, and the MOAS score is < 5.

The exclusion criteria were as follows: (1) Mental disorders and mental retardation caused by physical or brain diseases; (2) History of alcohol and psychoactive substance abuse; (3) History of traumatic brain injury and loss of consciousness for more than 30 minutes; (4) Audio-visual dysfunction; and (5) Blood or serious infectious diseases.

Sample size calculating

According to the calculation of 10 times the study variables, a total of 24 variables were involved in this study, that is, n = 24 × 10 × 120%= 288, so a total of 288 patients with schizophrenia were selected in this study.

At the same time, according to the formula n = 2 (μα+μβ) δ/β, where β = 0.2, α = 0.5. Finally, n = 100 was obtained, that is, the sample size of the healthy group was 100 cases.

Method

Patients’ general information, including gender, age, marital status, occupational status, drinking history, smoking history, and so on, was collected and regular follow-up conducted.

The fasting venous blood (4 mL) was collected from the two groups, and the sample serum was separated for five minutes by centrifuge at a speed of 5000r/minute. Furthermore, the serum myocardial enzyme spectrum was used for testing, and the operation was carried out in strict accordance with the relevant instructions of the kit. At the same time, the relevant experimental results and index changes were recorded and analyzed in detail. Among them, aspartate transferase (AST) kit was purchased from Shanghai Huzheng Biotechnology Co., LTD., purity: 99%, product number: Hhzt-4582; lactate dehydrogenase (LDH) kit was purchased from Shenzhen Zike Biotechnology Co., LTD., purity: 100%, product number: ZIKER006; creatine kinase creatine kinase (CK) kit was purchased from Shanghai Liemai BioEngineering Co., LTD., purity: 99%, code: LM-876416S; CK isoenzyme (CK-MB) kit was purchased from Guangzhou Orida Biotechnology Co., LTD., purity: 99%, code: ARD11095; A-hydroxybutyrate dehydrogenase (A-HBDH) kit was purchased from Shanghai Fusheng Industrial Co., LTD., purity: 98%, product number: FS14687.

Observation index

During the detection, five important indexes were mainly analyzed, including AST , LDH , CK, CK-MB and A-HBDH; the judgment range of each index was as follows: The normal value of AST was between 8 IU/L and 35 IU/L, the normal range of LDH is 109 IU/L to 245 IU/L, that of CK is 50 IU/L to 190 IU/L, of CK-MB is less than 24 ng/mL, and of A-HBDH is 70 IU/L to 180 IU/L.

Statistical analysis

Statistical Package for the Social Sciences 26.0 was used to analyze the study data. The measurement data were expressed as mean ± SD and t-tested. Counting data is expressed as [n (%)] and χ² test is used. P < 0.05 was considered statistically significant.

RESULTS

Comparison of myocardial enzyme indexes between patients with schizophrenia and healthy people

The indexes of serum myocardial enzymes in schizophrenic patients were higher than those in healthy group, P < 0.05, as shown in Table 1.

Table 1 Detection results of myocardial enzymes in schizophrenic patients and healthy groups.

Group	n	Aspartate transferase (IU/L)	Lactate dehydrogenase (IU/L)	Creatine kinase (IU/L)	Creatine kinase isoenzyme (ng/mL)	A-hydroxybutyrate dehydrogenase (IU/L)
Schizophrenia group	288	49.76 ± 25.56	213.26 ± 40.21	155.23 ± 55.92	22.17 ± 7.64	160.23 ± 30.67
Health group	100	27.41 ± 12.33	172.71 ± 10.68	100.34 ± 8.37	14.23 ± 2.11	125 ± 6.38
t value	-	8.406	9.956	9.770	10.250	11.392
P value	-	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001

Comparison of myocardial enzymes in patients with schizophrenia

The indexes of serum myocardial enzymes in the violent group were higher than those in the non-violent group (P < 0.05), as shown in Table 2.

Table 2 Expression level of myocardial enzymes in patients with different violent behaviors.

Group	n	Aspartate transferase (IU/L)	Lactate dehydrogenase (IU/L)	Creatine kinase (IU/L)	Creatine kinase isoenzyme (ng/mL)	A-hydroxybutyrate dehydrogenase (IU/L)
Violence group	123	75.67 ± 12.46	257.31 ± 15.43	219.34 ± 6.67	29.41 ± 6.23	195.38 ± 3.62
Non-violent group	165	30.61 ± 12.43	180.71 ± 11.34	107.84 ± 9.37	16.83 ± 2.34	134.24 ± 5.28
t value	-	30.400	48.566	112.418	23.795	110.493
P value	-	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001

Single factor analysis of influencing violence

Univariate analysis showed that irritability, previous aggressive behavior, AST, LDH, CK, CK-MB, A-HBDH were significantly related to the violent behavior of schizophrenics (P < 0.05). Gender, marital status, professional status, introversion, involuntary admission, major life events, anxiety, hostility, suspicion, hallucinations, behavioral disorders, drinking history, smoking history, hallucinations, etc. are not significantly related to the occurrence of violent behavior in schizophrenics (P > 0.05), as shown in Table 3.

Table 3 Single factor analysis of influencing violence, n (%).

Factor			Violence group	Non-violent group	t/χ²	P value
Gender	Men		54 (43.90)	75 (45.45)	0.069	0.793
	Women		69 (56.10)	90 (54.55)
Married			65 (52.84)	89 (53.94)	0.034	0.854
Inoccupation			77 (62.60)	97 (58.79)	0.429	0.513
Introverted			71 (57.72)	90 (54.55)	0.289	0.591
Irritability			75 (60.98)	62 (37.58)	15.471	0.000
Involuntary admission			50 (40.65)	79 (47.88)	1.489	0.222
Major life events			56 (45.53)	74 (44.85)	0.013	0.909
Depressed			66 (53.66)	94 (56.97)	0.313	0.576
Previous aggressive behavior			93 (75.61)	66 (40.00)	36.135	0.000
Anxious			1.58 ± 0.94	1.65 ± 1.12	0.561	0.575
Adopt a hostile attitude towards			3.04 ± 1.07	2.87 ± 1.08	1.327	0.186
Be suspicious			3.65 ± 1.45	3.19 ± 1.56	2.550	0.011
Hallucination			3.38 ± 1.68	3.15 ± 1.58	1.189	0.235
Behavior disorder			3.36 ± 1.39	3.14 ± 1.25	1.408	0.160
Drinking history			54 (43.90)	58 (35.15)	2.271	0.132
Smoking history			59 (47.97)	61 (36.97)	3.507	0.061
Number of hospitalization		≤ 3 times	76 (61.79)	119 (72.12)	3.441	0.064
		> 3 times	47 (38.21)	46 (27.88)
Course of a disease		< 6 months	22 (17.89)	49 (29.70)	5.441	0.066
		6-12months	54 (43.90)	59 (35.76)
		> 12months	47 (38.21)	57 (34.54)
Personality characteristics		Introvert	40 (32.52)	62 (37.57)	3.409	0.182
		Extroverted	30 (24.39)	26 (15.76)
		Intermediate personality	53 (43.09)	77 (46.67)
Aspartate transferase (IU/L)			75.67 ± 12.46	30.61 ± 12.43	30.400	< 0.001
Lactate dehydrogenase (IU/L)			257.31 ± 15.43	180.71 ± 11.34	48.566	< 0.001
Creatine kinase (IU/L)			219.34 ± 6.67	107.84± 9.37	112.418	< 0.001
Creatine kinase isoenzyme (ng/mL)			29.41 ± 6.23	16.83 ± 2.34	23.795	< 0.001
A-hydroxybutyrate dehydrogenase (IU/L)			195.38 ± 3.62	134.24 ± 5.28	110.493	< 0.001

Multivariate analysis

Taking whether schizophrenic patients have violent behavior as the dependent variable Y (non-violent group = 0, violent group = 1), logistic multivariate regression analysis shows that aggressive behavior, AST, CK and CK-MB are independent risk factors for schizophrenic patients to have violent behavior (P < 0.05), as shown in Table 4.

Table 4 Logistic multivariate analysis of violent behavior in schizophrenic patients.

Variable	B	SE	Wals	P value	Exp(B)	95%CI
Irritability	0.388	0.991	0.153	0.696	1.474	0.211	10.286
Previous aggressive behavior	1.117	0.564	3.920	0.048	3.054	1.011	9.225
Aspartate transferase (IU/L)	0.169	0.021	63.748	0.000	1.184	1.136	1.235
Lactate dehydrogenase (IU/L)	-0.029	0.035	0.678	0.410	0.971	0.906	1.041
Creatine kinase (IU/L)	0.091	0.032	8.239	0.004	1.095	1.029	1.165
Creatine kinase isoenzyme (ng/mL)	0.373	0.093	16.009	0.000	1.452	1.210	1.744
A-hydroxybutyrate dehydrogenase (IU/L)	0.042	0.113	0.138	0.711	1.043	0.835	1.302
Constant	-19.685	22.600	0.759	0.384	0.000

ROC verification

Receiver operating characteristic (ROC) results showed that the areas under the curve of previous aggressive behavior, AST, CK and CK-MB expression levels were 0.650, 0.930, 0.913 and 0.909 respectively, and the corresponding sensitivities were 72.40%, 89.40%, 91.10% and 87.80% respectively (Table 5 and Figure 1).

Figure 1 Receiver operating characteristic curve of violent behavior in patients with schizophrenia caused by previous aggressive behavior and serum myocardial enzyme level. AST: Aspartate transferase; CK: Creatine kinase; CK-MB: Creatine kinase isoenzyme.

Table 5 Diagnostic value analysis.

Index	Areas under the curve	Sensitivity	Specificity	95%CI	Youden's index
Previous aggressive behavior	0.650	72.40	57.60	0.586-0.714	0.300
Aspartate transferase (IU/L)	0.930	89.40	89.70	0.899-0.962	0.791
Creatine kinase (IU/L)	0.913	91.10	93.30	0.874-0.952	0.844
Creatine kinase isoenzyme (ng/mL)	0.909	87.80	87.30	0.872-0.947	0.751

DISCUSSION

As one of the common mental disorders, schizophrenia has different symptoms in each disease period, and different clinical types have their own symptoms[6], among which cardiovascular symptoms are more common. Because of the long course of the patient and the side effects of long-term medication, the serum myocardial enzyme activity of patients with schizophrenia is abnormal, and the illness and drug factors have a certain impact on the body of such patients with schizophrenia, which makes most patients exhibit violence and aggression[7]. Related research[8] indicates that the rate of violent behavior of mental patients in China is as high as 50%, which seriously threatens the personal safety of family members and medical staff.

This study compared the levels of serum myocardial enzymes in patients with schizophrenia and healthy people. The results revealed that the indexes of serum myocardial enzymes in patients were higher than those in healthy individuals. At the same time, whether patients with schizophrenia exhibited violent behavior was compared again. The results revealed that the indexes of serum myocardial enzymes in patients with violence were higher than those in patients without violence. Univariate analysis established that gender, introversion, major life events, and so on are the influencing factors of violent behavior in patients with schizophrenia. The reason analysis reveals differences between men and women in terms of physiological structure, hormone level and gene expression, which affects mood, behavior and cognitive function, and then affects the behavior performance of patients[9]. For unemployed individuals with schizophrenia, the lack of stable work and social activities limits their social skills and stress resistance, so that when faced with challenges or difficulties, they will be more inclined to take violent actions to deal with them[10]. At the same time, patients with introverted personality tend to be alone, which will lead to social isolation and loneliness, while patients with schizophrenia suffer from social discrimination, which further increases their psychological pressure and anxiety, and eventually leads to violence as a coping mechanism[11]. In addition, when patients experience major life events, such as the death of their loved ones and family breakdown, they will not only experience intense emotional trauma and psychological pressure, but their psychological state will also be affected, thus inducing or aggravating the symptoms of schizophrenia and further aggravating the risk of violent behavior[12]. In addition, depression will make patients with schizophrenia feel depressed, lose interest, lose energy, and other symptoms, thereby leading to their loss of confidence and enthusiasm for life. Furthermore, depression will further aggravate patients’ hallucinations, delusions, and other symptoms, resulting in strong anxiety and fear of the surrounding environment, which will lead to irritability and impulsiveness, and violent actions to deal with their inner fears and anxieties[13].

Aggressive behavior is often closely related to individual psychological characteristics and behavioral patterns. For patients with schizophrenia, aggressive behaviors may have been present in the past, which means that patients are more inclined toward violence when they are in trouble[14]. Once this behavior pattern is formed, similar situations in the future may trigger such behavior, thus increasing the risk of violent behavior[15]. The results of this study indicate that people with schizophrenia who have exhibited aggressive behavior in the past are more likely to lead to violent behavior. Logistic regression analysis established that aggressive behavior in the past is an independent risk factor leading to violent behavior in patients with schizophrenia. Reason analysis indicates that aggressive behavior in the past reflects patients’ psychological obstacles, including emotional instability, impulse control obstacles, social skills defects, and so on. These problems increase the risk of violent behavior to a certain extent[16], and when patients with schizophrenia have fantasies, delusions, and other symptoms, they may further aggravate these psychological problems[17]. At the same time, patients’ social relations and the surrounding environment have a negative impact, which will aggravate patients’ psychological pressure and troubles to a certain extent, thus making them more prone to aggressive behavior[18]. Therefore, patients who have already experienced violent behavior should take appropriate measures in time.

Because the serum myocardial enzyme activity of patients with schizophrenia will be abnormal, and myocardial enzyme is mainly distributed in skeletal muscle and myocardium, this is an important index to reflect myocardial damage[19]. When myocardial injury occurs, it can be released into the blood, which increases the corresponding enzyme activity in the blood, mainly related to the pathological changes of the brain nervous system and neuromuscular and biochemical immune system dysfunction[20]. This study documents that the contents of AST, CK and CK-MB in the violent group are significantly higher than those in the non-violent group, which indicates that the contents of AST, CK and CK-MB in the body are closely related to the severity of irritability, aggressive behavior, and schizophrenia symptoms. Further logistic regression analysis revealed that serum myocardial zymogram is an independent risk factor for violent behavior in patients with schizophrenia. The reason for this is that when psychotics are excited and aggressive, the sympathetic nerve of the body is excited, which increases the level of catecholamine hormones, thus stimulating the contraction of blood vessels in the whole body, causing ischemia and hypoxia in various organs and tissues[21]. This not only reduces the energy metabolism level of tissues and cells to a certain extent, but also increases the permeability of the tissue cell membrane, promotes CK to enter the blood circulation from cells, and leads to an increase in the level of serum CK[22]. At the same time, owing to the influence of the physiological, psychological environment, and social factors, patients with schizophrenia may experience brain dysfunction, which may affect mental activities such as cognition, consciousness, and emotion[23]. Since the clinical symptoms of patients with schizophrenia are not obvious at the initial stage of onset, disease progression is slow. With the recurrence of the disease and the aggravation of symptoms, patients are prone to impulsive behavior. To a certain extent, the body’s energy metabolism is vigorous and muscle movement is intense, which leads to a significant increase in the activities of myocardial enzymes such as AST, CK, and CK-MB, and the patient’s behavioral activities are closely related to the increase in CK levels[24]. In addition, when the patient exhibits violent behavior, the muscle tension of the skeletal muscles is significantly enhanced, which destroys the structure of tissue cells and damages muscle cells, thus increasing the level of serum myocardial enzymes[25].

ROC analysis of previous aggressive behavior and serum myocardial enzymes is of high value in predicting and evaluating violent behavior in patients with schizophrenia, and serum AST, CK, and CK-MB levels can be used as markers to evaluate their prognostic value.

CONCLUSION

In summary, a close relationship exists between the aggressive behavior of patients with schizophrenia in the past and the violent behavior of serum myocardial enzymes. However, although the relationship between myocardial enzyme levels and aggression has been identified in this study, further longitudinal studies are needed to investigate the causal relationship. At the same time, the serological indicators and biochemical markers of the results of this study will provide certain references for the diagnosis and treatment of aggressive behavior in schizophrenia patients, but the specific mechanisms of these biochemical indicators in the intervention methods and prognostic effects still need to be further studied. This also becomes the shortcoming of this study.