The effect of opioid dependence on conventional and novel biochemical parameters of bone metabolism.

BACKGROUND: Opioids influence bone metabolism in several ways and osteoporosis associated with the long-term use of opioids is believed to be multifactorial. OBJECTIVES: To investigate the effect of opioid dependence on conventional and novel biochemical parameters of bone metabolism. To evaluate whether the concomitant HCV infection affects these parameters. METHODS: Fifty-nine opioid-dependent subjects and 23 healthy volunteers participated in the study. Parameters of bone metabolism were determined in serum. The determined parameters were procollagen type I N-terminal propeptide (PINP), serum Beta-Crosslaps Ι (ß-CTX), total calcium (Ca), inorganic phosphorus (P), parathormone (PTH) and alkaline phosphatase bone isoenzyme (ALP). RESULTS: The results of our study show that opioid-dependent subjects exhibit higher values in those biochemical markers that are indicative of increased osteoclast activity, such as ß-CTX and ALP, compared to healthy subjects. Furthermore, in opioid-dependent subjects the values of PTH were lower, while those of PINP were higher, in comparison to healthy individuals. No significant difference in the studied parameters was found when opioid-dependent subjects positive for anti-HCV antibodies were compared with opioid-dependent subjects negative for anti-HCV antibodies. CONCLUSION: Our findings show that there is increased bone turnover (bone metabolism) in opioid-dependent subjects, compared to healthy individuals. Future research on bone mineral density in these patients will help us evaluate whether the bone remodeling process is balanced or not.

Alterations in serum MMP and TIMP concentrations following chronic heroin abuse.

UNLABELLED: Abstract Context: Although opiate abuse is known to affect matrix metalloproteinases (MMPs), data on these enzymes and their tissue inhibitors in heroin addicts are scarce. OBJECTIVE: In the present study, we determined serum concentrations of MMP-2, MMP-9, tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in heroin users, and compared them with healthy individuals. We evaluated whether 21 d of abstinence are adequate to reverse the effect of opiates and we compared seropositive with seronegative, for anti-HCV antibodies, heroin users. MATERIALS AND METHODS: Twenty-six heroin-dependent male volunteers and an equal number of healthy individuals participated in this study. ELISA was used to assess the serum levels of MMP-2, MMP-9, TIMP-1 and TIMP-2. Heroin users were assessed both upon admission and upon completion of a 21-d detoxification program. RESULTS: Serum TIMP-1 concentrations were significantly lower and the ratios MMP-2/TIMP-1, MMP-9/TIMP-1 and MMP-2/TIMP-2 were significantly higher in heroin users compared to healthy individuals. Heroin users who were seropositive had lower MMP concentrations, as well as lower MMP/TIMP ratios, compared to those who were seronegative. DISCUSSION: Our results showed that in heroin-addicted individuals, and especially those who are positive for anti-HCV antibodies, the balance between MMPs and TIMPs in serum is disrupted and this disruption cannot be restored within 21 d of abstinence. CONCLUSION: Chronic heroin abuse disrupts the balance between MMPs and TIMPs in serum and this effect is not reversible within 21 d of abstinence.

Global DNA methylation levels in white blood cells of patients with chronic heroin use disorder. A prospective study.

BACKGROUND: Increasing scientific evidence shows the significant role of epigenetic mechanisms in drug use disorder, abstinence and relapse. Studies on human subjects are limited compared to those on animals, for various reasons such as poly-substance abuse, high drop-out rate and technical difficulties. OBJECTIVES: Our goal was to evaluate whether a monitored abstinence period of 21 days could induce changes in global DNA methylation in chronic heroin users. METHOD: In the current study, we present data on global DNA methylation on a set of 18 male patients with chronic heroin use disorder, carefully selected based on inclusion and exclusion criteria, who were hospitalized and closely monitored during a 21-day detoxification program, one of the few where no opioid agonist is administered. The participants were sampled twice, once upon enrolment to the program and once upon completion. RESULTS: According to our results, no difference in global DNA methylation was detected between samples collected upon enrolment and samples collected upon completion of the program. CONCLUSION: The findings of this study do not rule out the possibility that the 21-day abstinence period was not long enough to observe changes in global DNA methylation, or that abstinence induced site-specific methylation changes (but not global changes), that certainly merit further evaluation.

Isoprostane as a marker of oxidative stress in chronic heroin users: correlation with duration of heroin use or concomitant hepatitis C infection.

BACKGROUND: Although chronic heroin abuse has been extensively linked to oxidative stress, and while plasma 15-F(2t)-IsoP is considered a good indicator of oxidative stress, there remain few references in the literature about the plasma concentration of this marker in heroin dependent subjects. OBJECTIVES: To determine plasma 15-F(2t)-IsoP, as a marker of oxidative stress, in chronic heroin users, and to examine whether the values of this marker correlate with the duration of heroin use or with the presence of anti-HCV antibodies. METHODS: Forty-two chronic heroin users and twenty two healthy control subjects were recruited for this study. An enzyme-immunoassay method was used for the determination of 15-F(2t)-IsoP in plasma. RESULTS: Plasma 15-F(2t)-IsoP values were significantly higher in chronic heroin users compared to healthy controls. No correlation was found between the values of plasma 15-F(2t)-IsoP and the duration of heroin use. Heroin dependent subjects positive for anti-HCV antibodies had significantly lower values of plasma 15-F(2t)-IsoP as compared to those without a history of HCV infection. CONCLUSIONS: The elevated plasma 15-F(2t)-IsoP values in heroin dependent subjects, compared to healthy individuals, indicate a shift of the balance between oxidants and antioxidants towards the former and suggest that heroin dependent subjects could benefit from an antioxidant therapy.

Evaluation of prooxidant-antioxidant balance in chronic heroin users in a single assay: an identification criterion for antioxidant supplementation.

BACKGROUND: Opiate abuse has been linked to oxidative stress, through the separate evaluation of oxidants and antioxidants. OBJECTIVES: To determine prooxidant-antioxidant balance (PAB) in chronic heroin users in a single assay, easily applied in a clinical setting. Specifically, to examine whether PAB values correlate with the duration of abuse or with the presence of anti-HCV antibodies. METHODS: Sixty-four chronic heroin users - 34 cases and 30 controls - participated in this study. PAB was determined by an Enzyme-linked immunosorbent assay (ELISA) method, developed by members of the study group. RESULTS: In heroin users, oxidative balance was disrupted in favor of prooxidants. There was no correlation of PAB values with the duration of abuse or with the presence of anti-Hepatitis C virus (HCV) antibodies. CONCLUSIONS: Chronic heroin users can benefit from an antioxidant therapy, and the method currently presented can be used as an identification criterion.

Opioids and the hormone oxytocin.

The neuropeptide Oxytocin (ΟΤ) is involved as a neurohormone, a neurotransmitter, or a neuromodulator in an extensive range of central and peripheral effects, complex emotional and social human behaviors, memory and learning processes. It is implicated in homeostatic, neuroadaptive processes associated with stress responses and substance use via interactions with the hypothalamic-pituitary-adrenal (HPA) axis and the dopamine mesolimbic reward stress system. This chapter reviews the preclinical and clinical literature on the complicated relationships between endogenous and exogenous opioids and ΟΤ systems and attempts to highlight key findings to date on the effectiveness of intranasal OT administration to treat opioid use disorders. OΤ seems to attenuate, even inhibit, the development of opioid use disorders in preclinical models but is still under clinical research as a promising pharmacological agent in the treatment of opioid use related behaviors. Evidence suggests a role for OT as an adjunctive or stand-alone treatment of behavioral, cognitive and emotional deficits associated with substance use, which may be responsible for seeking behavior and relapse. The mechanisms by which oxytocin acts to reverse the neural substrates of these deficits, partially due to substance induced alterations of the endogenous OT system, and thus modify the behavioral response to substance use are discussed. Other clinically relevant issues are also discussed.

Severity of Withdrawal Symptoms, Plasma Oxytocin Levels, and Treatment Outcome in Heroin Users Undergoing Acute Withdrawal.

Pre-clinical studies show that, following chronic opioid exposure, oxytocin neurons exhibit over-excitation upon withdrawal, causing an increase in oxytocin brain and plasma levels. Relevant clinical data on humans are scarce. This study investigates the opioid withdrawal stress effect on oxytocin plasma levels in humans. We evaluated 57 male chronic heroin users in a residential detoxification program. We determined plasma oxytocin levels by ELISA and measured the stress effects of withdrawal using the COWS scale for opioid withdrawal, the VAS scale for craving, and the Hamilton scales for anxiety and depression on the second day of admission. Out of the 57 patients enrolled in the study, 27 completed the 21-day program, while the remaining 30 dropped out prior to completion. Plasma oxytocin levels were significantly higher in those individuals who dropped out than in those who completed the program. Participants who dropped out at some stage scored higher in the COWS, VAS-Craving, and Hamilton-anxiety scales, indicating a higher stress and explaining the higher oxytocin levels. In addition, plasma oxytocin levels correlated positively with the scores achieved in the COWS and Hamilton-anxiety scales. Higher withdrawal stress levels are associated with higher plasma oxytocin levels and early treatment discharge.