Ethnic differences in complement system biomarkers and their association with metabolic health in men of Black African and White European ethnicity.

Inflammation plays a fundamental role in the development of several metabolic diseases, including obesity and type 2 diabetes (T2D); the complement system has been implicated in their development. People of Black African (BA) ethnicity are disproportionately affected by T2D and other metabolic diseases but the impact of ethnicity on the complement system has not been explored. We investigated ethnic differences in complement biomarkers and activation status between men of BA and White European (WE) ethnicity and explored their association with parameters of metabolic health. We measured a panel of 15 complement components, regulators, and activation products in fasting plasma from 89 BA and 96 WE men. Ethnic differences were statistically validated. Association of complement biomarkers with metabolic health indices (BMI, waist circumference, insulin resistance, and HbA1c) were assessed in the groups. Plasma levels of the key complement components C3 and C4, the regulators clusterin and properdin and the activation marker iC3b were significantly higher in BA compared to WE men after age adjustment, while FD levels were significantly lower. C3 and C4 levels positively correlated with some or all markers of metabolic dysfunction in both ethnic groups while FD was inversely associated with HbA1c in both groups, and clusterin and properdin were inversely associated with some markers of metabolic dysfunction only in the WE group. Our findings of increased levels of complement components and activation products in BA compared to WE men suggest differences in complement regulation that may impact susceptibility to poor metabolic health.

A Systematic Review of Beta Cell Function in Adults of Black African Ethnicity.

BACKGROUND: Understanding ethnic differences in beta cell function has important implications for preventative and therapeutic strategies in populations at high risk of type 2 diabetes (T2D). The existing literature, largely drawn from work in children and adolescents, suggests that beta cell function in black African (BA) populations is upregulated when compared to white Europeans (WE). METHODS: A systematic literature search was undertaken in June 2018 to identify comparative studies of beta cell function between adults (>age 18 years) of indigenous/diasporic BA and WE ethnicity. All categories of glucose tolerance and all methodologies of assessing beta cell function in vivo were included. RESULTS: 41 studies were identified for inclusion into a qualitative synthesis. The majority were studies in African American populations (n = 30) with normal glucose tolerance (NGT)/nondiabetes (n = 25), using intravenous glucose stimulation techniques (n = 27). There were fewer studies in populations defined as only impaired fasting glucose/impaired glucose tolerance (IFG/IGT) (n = 3) or only T2D (n = 3). Although BA broadly exhibited greater peripheral insulin responses than WE, the relatively small number of studies which measured C-peptide to differentiate between beta cell insulin secretion and hepatic insulin extraction (n = 14) had highly variable findings. In exclusively IGT or T2D cohorts, beta cell insulin secretion was found to be lower in BA compared to WE. CONCLUSIONS: There is inconsistent evidence for upregulated beta cell function in BA adults, and they may in fact exhibit greater deficits in insulin secretory function as glucose intolerance develops.

Phacoemulsification with aspirated or retained Viscoat.

Endothelial cell counts, morphology, and 24-hour postoperative intraocular pressure (IOP) changes were measured in 55 consecutive patients (60 eyes) who had uncomplicated phacoemulsification and posterior chamber lens implantation with either aspirated (30 eyes) or retained (30 eyes) Viscoat (sodium chondroitin sulfate-sodium hyaluronate). The surgical technique was standardized in all cases. Endothelial cell loss was almost identical in the aspirated and in the retained groups (8.8% and 8.7%). Postoperative pleomorphism was significantly less in the retained Viscoat group than in the aspirated group, suggesting a possible protective effect of the retained viscoelastic. Corneal thickness increased significantly in the retained Viscoat group, but this was not significant clinically. The retained Viscoat group had more patients with a postoperative IOP greater than 30 mm Hg and a greater mean increase in postoperative IOP, although the difference between the groups was not significant. The IOP changes may have been caused by blockage of the trabecular meshwork by the retained Viscoat. The results suggest that Viscoat can be retained after cataract surgery if the surgeon is prepared for a greater 24-hour postoperative increase in IOP.

Changes in astigmatism after surgery for congenital ptosis.

To determine the effect of ptosis surgery on the astigmatic refractive error in pediatric patients, we assessed 88 eyes postoperatively at 3, 6, and 12 months. Thirty-six eyes of unilateral cases were used as controls. There was an overall increase in average astigmatic refractive error of the study group by 0.30 diopters, while the control group decreased 0.15 D. Thirty-six percent of study eyes changed by more than 0.75 D. Results were similar for both fascia lata slings and levator resections. Those patients older than 4 years showed an increase in average cylinder (0.50 D), while those younger than 4 years decreased their average cylinder (0.20 D). Careful monitoring with postoperative refractions is required in pediatric ptosis patients.

Topical 2.5% and 5% phenylephrine: comparison of effects on heart rate and blood pressure.

We compared the effects of 2.5% and 5% concentrations of topical ocular phenylephrine hydrochloride on blood pressure and heart rate in 200 adult patients undergoing extracapsular cataract surgery under either general or neuroleptic anesthesia. Although there was little initial change in mean systolic or diastolic blood pressure in either group, once anesthesia was induced there was a rise of 1 to 5 mm Hg in the lower-dose group, compared with 17 to 26 mm Hg in the higher-dose group. A slight decrease in mean heart rate of 5 to 6 beats/min was noted immediately after the instillation of either the 2.5% or 5% solution. The results suggest that lower doses of topical phenylephrine are safer than higher doses when used preoperatively. This may be particularly significant in hypertensive patients, who have higher baseline blood pressure.

Coronary artery spasm with sinus node dysfunction and syncope.

In a 55-year-old man, attacks of spontaneous angina were associated with dizziness and syncope. Holter ECG monitoring disclosed evidence of sinus node dysfunction. Dizziness and syncope were corrected by a permanent ventricular demand pacemaker. Coronary cineangiography showed spontaneous, severe, diffuse spasm in a dominant left coronary artery and localized spasm in a nondominant right coronary artery. The patient died of pump failure shortly after cardiac catheterization. An autopsy disclosed only minimal coronary atherosclerosis. This patient's condition shows that (1) coronary spasm may cause sinus node dysfunction, dizziness, and syncope, (2) severe spasm that involves all the coronary artery branches may be fatal, and (3) severe spasm occur in minimally diseased coronary arteries confirmed by pathologic examination.