(For moderators: no need to remove text in quotations - the original article is published under the Creative Commons license)
I was reading up on the possible action of taurine in the body, and googled all kinds of word combinations and ended up with this recent article↓
I got curious about MMP-9 because I’ve long known that it’s increased in keratoconus, which I have (but now I have the genes for it only, since my corneas were replaced with transplants). It was reported as increased in corneas in keratoconus, but I’m not sure about blood serum samples.
Here’s the abstract:
Background
Matrix metalloproteinases (MMPs) are a diverse set of enzymes associated with inflammation. MMP-9 is of particular interest because it has been associated with autoimmune and cardiopulmonary disorders, tobacco smoking, and obesity, prevalent in psychiatric populations.
Methods
Sensitive enzyme immunoassays measured MMP-9 in blood samples from 1121 individuals (mean age = 35.6 [SD = 13.0] years; 47.7% male; 440 with schizophrenia, 399 with bipolar disorder, and 282 without a psychiatric disorder). We estimated the odds of diagnosis associated with MMP-9, demographic variables, tobacco smoking, and obesity, and also the partial explained variance using regression methods. We also determined the association between psychiatric medications and MMP-9 levels.
Results
Individuals with elevated MMP-9 levels had higher odds of schizophrenia or bipolar disorder compared with the nonpsychiatric group adjusted for demographic variables. Partial correlation analyses indicated the demographic-adjusted variance associated with MMP-9, smoking, obesity, and their interaction explained 59.6% for schizophrenia and 39.9% for bipolar disorder. Levels of MMP-9 were substantially lower in individuals receiving valproate, particularly relatively high doses.
Conclusions
Individuals with higher levels of MMP-9 have significantly higher odds of schizophrenia or bipolar disorder. Individuals receiving valproate had substantially lower levels of MMP-9, possibly related to its ability to inhibit histone deacetylation. A substantial portion of the variance in clinical disorders associated with MMP-9 can be attributed to smoking or obesity. Interventions to reduce smoking and obesity might reduce the morbidity and mortality associated with elevated MMP-9 levels and improve the health outcomes of individuals with these disorders.
and just one little quotation from the Discussion section:
The results of this study are consistent with those of several other studies in showing elevated levels of MMP-9 in individuals with schizophrenia (27, 28, 29, 30, 31). Several additional studies have not shown this association, but they have had small samples sizes and/or did not adjust for smoking status or obesity (32,33). Further studies should include smoking and obesity and other environmental factors in order to maximize reproducibility across studies. MMP-9 levels have also been associated with decreased cognitive functioning in individuals with schizophrenia (34,35).
