Observational and epidemiological studies suggest that a continuum of risk may exist for blood pressure, body weight, glucose and lipids, which, in combination ...
Clin. Lab. 2007;53:XXX-XXX ©Copyright
ORIGINAL ARTICLE
Lipid and Lipoprotein Profile in Physiological Pregnancy GIUSEPPE LIPPI1, ALESSANDRO ALBIERO2, MARTINA MONTAGNANA1, GIAN LUCA SALVAGNO1, SILVIA SCEVAROLLI2, MASSIMO FRANCHI2, GIAN CESARE GUIDI1 1
Sezione di Chimica e Microscopia Clinica, Dipartimento di Scienze Morfologico-Biomediche, Università di Verona, Italy 2 Unità di Ostetricia, Dipartimento Materno ed Infantile, Università di Verona, Italy
SUMMARY Physiologic pregnancy is associated with a broad series of metabolic adaptations which may also influence the metabolism of lipids and lipoproteins. Although the modification of serum lipids and lipoproteins has been exhaustively investigated during and after pregnancy, the relative changes recorded vary widely among the different studies. A comprehensive lipid and lipoprotein profile was evaluated in 57 women with uncomplicated pregnancies at different gestational ages (20 in the first, 20 in the second, and 17 in the third trimester of pregnancy) and compared to that of 21 non-pregnant women. Conventional lipid parameters, including total cholesterol, high density lipoprotein cholesterol and triglycerides, were evaluated on the Modular System P. Low density lipoprotein cholesterol was quantified by the formula of Friedewald, the atherogenic index of plasma was quantified by the formula log(triglycerides/high density lipoprotein cholesterol), whereas lipoprotein(a) was assayed on the BN II nephelometric analyzer. We observed that all the lipid parameters tested were significantly modified by the gestational age; in particular, women in the second and third trimester displayed significantly increased total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, total to high density lipoprotein cholesterol ratio, lipoprotein(a) and atherogenic index of plasma (third trimester only) when compared to either the control population or the subgroup of women in the first trimester of pregnancy. The value distributions and the relative percentage of women with undesirable or abnormal values according to the current NCEP or AHA/ACC goals were comparable between controls and women in the first trimester. However, when compared with either controls or women in the first trimester, advanced pregnancy was associated with an increased prevalence of undesirable or abnormal values for total cholesterol, low density lipoprotein cholesterol and triglycerides in the second trimester, and total cholesterol, low density lipoprotein cholesterol, triglycerides, total to high density lipoprotein cholesterol ratio and lipoprotein(a) (only from non-pregnant women) in the third trimester. The results of this case-control study demonstrate that physiological pregnancy is associated with a substantial modification of the lipid and lipoprotein metabolism from the second trimester, providing reference ranges for traditional and emerging cardiovascular risk predictors throughout the gestational period. (Clin. Lab. 2007;53:XXX-XXX)
KEY WORDS Pregnancy, cardiovascular risk, cholesterol, lipoprotein(a).
INTRODUCTION Atherosclerosis results from a complex interaction between genetic and environmental factors, dominated by those associated with nutrition. Atherogenesis begins much earlier than previously suspected, developing inClin. Lab. 3+4/2007
conspicuously for many decades before the manifestation of clinical symptoms and cardiovascular complications which usually occur in middle and late age. There are several reasons for investigating the lipid and lipoprotein profile during pregnancy. First, atherogenesis is not restricted to the postnatal period, as several biochemical mechanisms that influence the development of atherosclerosis are active already during pregnancy [1]. Fatty streak formation, a hallmark of atherosclerosis,
Manuscript accepted
GIUSEPPE LIPPI et al.
Table 1: Lipids and other biochemical parameters in 21 non-pregnant women and 57 pregnant women at different gestational age. Values are shown in mean and standard deviation, with the exception of lipoprotein(a) (median and 5-95 percentile distribution).
n Total cholesterol (mg/dl) HDL-C (mg/dl) LDL-C (mg/dl) Triglycerides (mg/dl) Total to HDL-C ratio AIP Lipoprotein(a) (mg/l)
Control women 21 183±25 69±10 99±23 77±34 2.7±0.5 0.01±0.20 117 (37-298)
Pregnancy 1st trimester 20 173±18 67±12 90±17 79±27 2.6±0.4 0.05±0.17 99 (30-373)
2nd trimester 20 243±53†‡ 83±19†‡ 130±46†‡ 151±80†‡ 3.0±0.8 0.22±0.23† 244 (38-901)†‡
3rd trimester 17 267±30†‡ 81±17†‡ 136±33†‡ 245±73†‡ 3.4±0.7†‡ 0.47±0.17†‡ 280 (27-1266)†‡
LDL-C, low-density lipoprotein cholesterol; HDL-C, high-density lipoprotein cholesterol, AIP, atherogenic index of plasma. Differences are evaluated by unpaired Student’s t-test or the Mann-Whitney test, when appropriate. † p
