Læknablaðið - 15.11.1990, Blaðsíða 48

468
LÆKNABLAÐIÐ
SKIMAÐ FYRIR ERFÐAGALLA í APOPRÓTÍN-B
í ÍSLENSKUM FJÖLSKYLDUM MEÐ HÆKKAÐ
KÓLESTERÓL f SERMI
Vilmundur Guðnason, Gunnar Sigurðsson.
Lvflækningadeiid Borgarspítala, The Charing Cross
Sunley Research Center, London.
Nýlega var lýst fjölskyldum í Bandaríkjunum og Bretlandi
með erfðagalla í apo-B-100 (aðalburðarprótín í LDL)
valdandi því að glutamín er sett inn í prótínið í stöðu
3500 í stað arginins í heilbrigðu prótíni. Þessi breyting
veldur því að apo-B binst verr við LDL-viðtakann, meðal
annars á lifrarfrumunum, sem taka því minna upp af LDL
og afleiðingin verður hækkað LDL-kólesteról í blóði.
Við leituðum eftir þessum erfðagalla í DNA hvítra
blóðkoma frá 50 óskyldum íslendingum með verulega
hækkun á kólesteróli og flestir þeirra höfðu ættarsögu
um hækkað kólesteról. Við rannsóknina var beitt
nýlegri aðferð þar sem DNA er magnað upp með
fjölliðunarensími (polymerase chain reaction, PCR)
og síðan notaðir sætissértækir þreifar (aliele specific
oligonucleotides, ASO) til að greina stökkbreytinguna
í apo-B geninu. Þessi rannsóknartækni hefur mtt sér til
rúms á síðustu árum en okkur er ekki kunnugt um að
henni hafi verið beitt áður við íslenska rannsókn.
Ekkert þessara 50 íslensku sýna reyndist jákvætt með
tilliti til þessa galla í apo-B geninu. Tíðni þessa erfðagalla
virðist því talsvert mismunandi eftir þjóðlöndum en telja
verður líklegt að fleiri stökkbreytingar en í amínósýru
n=3500 séu orsök fyrir arfbundinni hækkun á kólesteróli
og skýrist það væntanlega á næstu árum. Ef svo reynist
vera þá mun sú tækni sem hér var notuð koma að gagni
við slíka greiningu þegar í bamæsku.
HYPERCHOLESTEROLAEMIA AS A RISK
FACTOR FOR CORONARY HEART DISEASE
Hans Lithell. Department of Geriatrics, Uppsala
University, Uppsala, Sweden.
Coronary heart disease is the most prevalent death cause
among Scandinavian men and women and has been
increasing up to the beginning of the 80’s. The relatively
high incidence of coronary heart disease seems to be a
great part related to »environmental« factors. All the
most important risk factors for coronary heart disease -
high blood pressure, hypertension, hypercholesterolaemia
and smoking - are directly related to the life style of the
individual. It is today recommended that all treatment of
hypertension as well as hyperlipidaemia should start with
non-pharmacological intervention. Prospective randomised
trials have shown that intervention of smoking habits and
diet have an impressive effect in reducing the risk for
coronary heart disease. Treatment of hypertension reduces
the risk for stroke. For those patients where treatment
with non-pharmacological means does not normalise the
high cholesterol value, possibly due to genetic factors,
pharmacological treatment is recontmended. Several of
these drugs have been used in prospective trials and the
effect in reducing cholesterol and risk for coronary heart
disease has been verified. A new series of agents, HmG-
CoA-reductase inhibitors, are very effective and have few
side effects and in these respect are superior to many of
the older drugs. At the present time, long-term safety data
and the results in terms of reduced risk for coronary heart
disease are still lacking but prospective trials have been
started to evaluate safety aspects and risk reducing effects.
LONG TERM EFFECTS OF ANTIHYPERTENSIVE
TREATMENT ON GLUCOSE AND LIPID
METABOLISM
Hans Lithell, E. Skarfors, T. Pollare, C. Berne.
Department of Geriatrics, Uppsaia, Sweden.
A health survey was performed in a male population
(n=2322) at the age of 50 years and ten years later. An
intravenous glucose tolerance test (IVGTT) with insulin
determinations was done together with measurement of
blood pressure, serum lipid and lipoprotein fractions and
body weight, among other examinations. The incidence of
NIDDM in a group of treated hypertensives was several
times higher than in a control group of men with similar
body mass index and serum triglyceride and cholesterol
values and similar glucose tolerance measured as the k
value of an IVGTT. However, insulin concentrations were
higher among hypertensives who developed NIDDM than
among those who did not.
In the whole cohort body mass index, fasting
serum insulin, low insulin index and high late
glucose concentrations at IVGTT were risk factors
for development of diabetes. Furthermore, use of
antihypertensive medication was an independent risk
factor also after adjustment for the effect of insulin
concentrations and other risk factors and doubled the risk.
All agents discussed were similarly effective in reducing
blood pressure, but they had very different effects on
metabolic characteristics, particularly insulin sensitivity.
Treatment with the ACE inhibitor captopril resulted
in increased insulin sensitivity with no adverse effects
on lipids. Treatment with metoprolol and atenolol
(beta,-selective blocking agents) was associated with
decreased insulin sensitivity and increased fasting values
of insulin and glucose. There were indications of a
suppressive effect on insulin secretion during IVGTT;
an increase in serum triglycerides and a decrease in
serum highdensity lipoprotein cholesterol also occurred
during these treatments. Hydrochlorothiazide treatment
was associated with a decrease in insulin sensitivity and
an icrease in blood glucose concentrations. It increased
total cholesterol, particularly the low density lipoprotein
fraction. Diltiazem (a calcium-channel blocker) did not
appear to have any negative metabolic effects.
ÚTSKILNAÐUR ELEKTROLÝTA,
BLÓÐÞRÝSTINGUR OG ÞYNGD, MEÐAL 200
EINSTAKLINGA
Jóhann Ragnarsson, Gunnar Sigurðsson, Þóra
Karlsdóttir. Lvflækningadeild Borgarspítala.
Meðal 200 einstaklinga völdum af handahófi á aldrinum
20-59 ára, jafnt af báðum kynjum (skipt í 8 hópa),
var safnað sólarhringsþvagi. Söfnunin hófst og endaði
á deildinni. Mæld var þéttni natríums, kalíums, klórs
kalsíums, magnesíums og kreatínins í þvagi ásamt
þvagmagni. Einnig var mældur blóðþrýstingur, tvisvar í
sitjandi stöðu eftir 5 mín. hvíld. Hæð og þyngd var skráð
ásamt fleiri upplýsingum.