New-onset extremely low levels of high-density lipoprotein cholesterol

High-density lipoprotein cholesterol and multiple myeloma: A systematic review and meta-analysis

Background and aims

To systematically investigate all relevant evidence on the association between high-density lipoprotein cholesterol (HDL-C) and multiple myeloma (MM).

Methods

We searched PubMed and Cochrane library databases (up to 20 September 2022) for studies with evidence on HDL-C in patients with MM. A qualitative synthesis of published prospective and retrospective studies for the role of HDL-C and other lipid profile parameters in MM was performed. Additionally, a meta-analysis on HDL-C mean differences (MD) between MM cases and controls was performed.

Results

Fourteen studies (3 prospective, 11 retrospective) including 895 MM patients were eligible for this systematic review. Ten studies compared HDL-C levels in MM patients with healthy controls. In these 10 studies (n = 17,213), pooled analyses showed that MM patients had significantly lower HDL-C levels compared to healthy controls (MD: -13.07 mg/dl, 95% CI: -17.83, -8.32, p < 0.00001). Regarding secondary endpoints, total cholesterol (TC) (MD: -22.19 mg/dl, 95% CI: -39.08, -5.30) and apolipoprotein A-I (apoA-I) (-40.20 mg/dl, 95% CI: -55.00, -25.39) demonstrated significant decreases, while differences in low-density lipoprotein cholesterol (LDL-C) (MD: -11.33 mg/dl, 95% CI: -36.95, 14.30) and triglycerides (MD: 9.93 mg/dl, 95% CI: -3.40, 23.26) were not shown to be significant.

Conclusions

HDL-C, as well as TC and apoA-I, levels are significantly decreased in MM. Hence, lipid profile parameters should be taken into account when assessing such patients.

High-density lipoprotein cholesterol: A marker of COVID-19 infection severity?

BACKGROUND AND AIMS

To systematically address all the relevant evidence of the association between high-density lipoprotein cholesterol (HDL-C) and COVID-19 infection.

METHODS

We searched PubMed, PubMed Central and medRxiv databases (up to May 2021) for studies related to HDL-C and COVID-19 infection. A qualitative synthesis of published prospective and retrospective studies for the role of low HDL-C levels on COVID-19 infection severity was performed.

RESULTS

Thirty-three studies (6 prospective, 27 retrospective) including 11,918 COVID-19 patients were eligible for the systematic review. Twelve studies compared HDL-C levels on admission in COVID-19 patients with healthy controls. In these 12 studies, COVID-19 patients had significantly lower HDL-C levels on admission compared with that of healthy controls. Twenty-eight studies observed the HDL-C levels among COVID-19 diagnosed patients, to establish the role of low HDL-C values in the prognosis of the infection. Twenty-four studies showed a correlation between low HDL-C levels with disease severity, while only 4 studies showed no association.

CONCLUSIONS

Low HDL-C levels should be added in the list of the others well-known risk factors for COVID-19 severity.

Diagnostic lipid changes in patients with visceral leishmaniasis

BACKGROUND

Visceral leishmaniasis (VL) has been associated with the increase in triglyceride (TG) levels and the decrease in high-density lipoprotein cholesterol (HDL-C) concentration. The aim of the study was to evaluate whether there is a diagnostic cut-off point in these lipid profile changes.

MATERIALS AND METHODS

We included 100 patients with febrile infections. Analytically, 22 patients with VL, 18 patients with leptospirosis, 20 patients with Brucella melitensis, and 40 age- and sex-matched patients with fever and proven bacteremia (endocarditis and pyelonephritis). The lipid parameters were assessed for their diagnostic accuracy using logistic regression and receiver operating characteristic statistics.

RESULTS

It was observed that coexistence of HDL-C < 15 mg/dL and ΤG > 180 mg/dL had 100% sensitivity and 67.5% specificity for the confirmation of VL. The corresponding positive and negative predictive values were 59.4% and 100%, respectively.

CONCLUSION

Coexistence of high TGs and low HDL-C values may suggest VL infection in a febrile patient.

Lipid testing in infectious diseases: possible role in diagnosis and prognosis

INTRODUCTION

Acute infections lead to significant alterations in metabolic regulation including lipids and lipoproteins, which play a central role in the host immune response. In this regard, several studies have investigated the role of lipid levels as a marker of infection severity and prognosis.

SCOPE OF REVIEW

We review here the role of lipids in immune response and the potential mechanisms underneath. Moreover, we summarize studies on lipid and lipoprotein alterations in acute bacterial, viral and parasitic infections as well as their diagnostic and prognostic significance. Chronic infections (HIV, HBV, HCV) are also considered.

RESULTS

All lipid parameters have been found to be significantly dearranged during acute infection. Common lipid alterations in this setting include a decrease of total cholesterol levels and an increase in the concentration of triglyceride-rich lipoproteins, mainly very low-density lipoproteins. Also, low-density lipoprotein cholesterol, apolipoprotein A1, low-density lipoprotein cholesterol and apolipoprotein-B levels decrease. These lipid alterations may have prognostic and diagnostic role in certain infections.

CONCLUSION

Lipid testing may be of help to assess response to treatment in septic patients and those with various acute infections (such as pneumonia, leptospirosis and others). Diagnostically, new onset of altered lipid levels should prompt the clinician to test for underlying infection (such as leishmaniasis).

Visceral leishmaniasis is associated with marked changes in serum lipid profile

BACKGROUND

Infection is often accompanied by lipid profile alterations. The aim of this study was to evaluate the lipid profile changes in patients with visceral leishmaniasis (VL).

MATERIALS AND METHODS

We included 15 patients [10 men, aged 50 (24-82) years old] with VL and 15 age- and sex-matched controls. The parameters estimated at diagnosis and 4 months after VL resolution were total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides (TGs), low-density lipoprotein cholesterol (LDL-C), apolipoproteins (apo) A-Ι, B, E, C-II, C-III, lipoprotein (a) [Lp(a)], activities of lipoprotein-associated phospholipase A2 (Lp-PLA2), HDL-Lp-PLA2, PON1 (paraoxonase 1) and cholesterol ester transfer protein (CETP), cytokines (interleukins 1β and 6 and tumour necrosis factor α), as well as LDL subfraction profile.

RESULTS

Patients with VL at diagnosis had lower levels of TC, LDL-C, apoΒ and Lp(a), and higher TG and apoE concentrations compared with 4 months after VL resolution. The activities of Lp-PLA2, HDL-Lp-PLA2 and ΡΟΝ1 were reduced at diagnosis compared with post-treatment values. VL patients had decreased levels of both large and sdLDL-C at diagnosis; no effect on mean LDL particle size was observed. Patients with VL at diagnosis had decreased HDL-C and apoA-I concentrations; these increased 4 months after VL resolution, but remained lower compared with controls. The activities of HDL-Lp-PLA2 and PON1 remained lower in patients after VL resolution compared with controls.

CONCLUSIONS

Patients with VL exhibit increased TG levels and decreased cholesterol subclasses at diagnosis. HDL-C, apoA-I and associated enzymes remain lower 4 months after VL resolution compared with controls.