Lipid metabolism in prediabetics

Atherosclerosis Elsevier Publishing

LIPID

Company,

METABOLISM

M. N. MIKHAIL, FAHMY

F.

K.

Amsterdam

IN PREDIABETICS

GUIRGIS,

Departments of Clinical Pathology Alexandria (Egypt) (Revised,

51

- Printed in The Netherlands

M. M. ABDEL-HAI,

and Medicine,

Faculty

M. H. of Medicine,

GHANEM Alexandria

AND

M. H.

University,

received January lSth, 1972)

SUMMARY

Significant elevation of various blood lipid constituents was demonstrated in 100 apparently healthy prediabetic subjects who were close relatives of known diabetic patients. According to their response to prednisone-primed glucose tolerance, these prediabetic subjects were classified into: 29 cases showing an abnormal response who were considered to have latent chemical diabetes, and 71 cases with a normal response who were referred to as potentially diabetic subjects. A group of 42 patients who had asymptomatic (or chemical) diabetes was also investigated. All subjects included in the present study were selected to be non-obese. They were matched for age, sex and socio-economic class as in the control group of 81 healthy individuals who had no family history of diabetes and whose prednisone-primed glucose tolerance was normal. A positive relation was found between the stage of the diabetic state and the abnormality of the blood lipid concentrations. Significant increase of the cholesterol/ phospholipid ratio and the beta/alpha-lipoprotein

ratio was noticed in potentially

diabetic subjects, suggesting their proneness to develop atherosclerosis. At this relatively early stage of the disease, the response of the circulating free fatty acids to intravenous administration of either glucose, insulin or glycodiazine was abnormal. The initial drop was significantly subnormal, the nadir was evidently delayed and the subsequent secondary rise was significantly slower than that of controls. As in diabetics, adipose tissue seemed to be relatively insensitive to the antilipolytic action of insulin and, in addition, we suggest that post-heparin lipoprotein lipase activity may have been diminished.

Key words: Blood li@ds - Free fatty acids - Glucose tolerance - Li$o$roteins

- Pre-

diabetes

Atherosclerosis,

1972, 16: 51-60

52

M. N. MIKHAIL

et id.

INTRODUCTION

In recent years, interest has been given to the biochemicalchanges ly healthy

subjects

who are genetically

among these prediabetic before appearance

subjects

early stage of the diabetic

on a relatively

about

state.

large number

of the disease

to develop

metabolism.

atherosclerosis

has been frequently

tackled

of results even among patients

encouraged

of subjects

It

at this by other

with clinically

us to carry out a more detailed study

who were selected on a solid genetic basis10

various stages of the diabetic

statellsl2.

AND METHODS

After an overnight prediabetic parents

of blood lipids

of carbohydrate

the liability

This subject

This controversy

and were grouped to represent MATERIAL

derangement

but with discrepancies

overt diabetess-9.

Study

might help in more precise diagnosis

of any demonstrable

may also provide information investigatorsl-3,

prone to be diabetic.

in apparent-

subjects

diabetic,

who were relatives

33%

and the remaining were selected

fast, blood lipids were estimated

in 100 apparently

of known diabetic

had one parent diabetic

in addition

patients;

28%

to another

healthy had both

close relative,

39 o/ohad either one parent or another close relative diabetic.

to be non-obese

and of standard

weight.

All had normal

They

oral glucose

tolerance. According

to the results

these prediabetic tolerance

subjects

of prednisone-primed

were classified

and were considered

whom the response intolerance

to have latent

was normal

denoting diabetic

Blood lipids which were estimated serum triglycerides

(TG)15,

The lipoprotein

trationzo,

total

pattern

chemical

control individuals

tolerance

(PPGT)2713,

diabetes12 and (2) 71 cases in

of any marker

CAMERINI-DAVALOS

of carbohydrate these cases

et d.ll,

subjects. included

and esterified

plasma

free fatty

cholesteroll6J7,

was also studiedlg,

as well as the cholesterol/phospholipid

(B/A) ratios21 were calculated.

glucose

(1) 29 cases who showed impaired

absence

even after stress. As suggested by

will be referred to as potentially

(PL)lS.

into:

acids

(FFA)I4,

and phospholipids

and the total lipoprotein

concen-

(C/P) and beta/alpha-lipoprotein

The same investigations

were carried out on 81 healthy

who had no family history of diabetes and their PPGT was normal.

They were selected to be non-obese

and of comparable

age, sex and body weight as the

prediabetics.

Pregnant

and lactating

females

as well as those who were receiving

contraceptive

pills or had an abnormal

obstetric

history

interpretation

of the results, 42 patients

Their diabetic

state was mild in degree, asymptomatic

They were receiving

neither diabetic

The data concerning

changes

diabetic

1972, 16: 5 I-60

diabetes

To facilitate

were also studied.

and discovered

accidentally.

P age, sex, height and weight of the various groups of sub-

in’therbloodVglucose22 L L

Atherosclerosis,

were excluded.

nor drug treatment.

jects included in this work are illustrated In potentially

having chemical

subjects

in Table

1.

who had both parents

and- FFA

levels were studied,

diabetic,

the dynamic

along the course of 3

LIPID METABOLISM

TABLE AGE,

53

IN PREDIABETICS

I

SEX,

HEIGHT

AND

WEIGHT

Total number

Controls Prediabetics Chemical diabetics

OF SUBJECT

GROUPS

Sex

Mean f

male

female

age (years)

height (cm)

weight (kg)

81 100

49 53

32 47

38.5 5 7.7 36.4 * 6.3

167.8 * 6.2 166.7 f 6.6

69.9 3 8.5 70.0 & 8.3

42

25

17

40.1 * 7.9

168.0 h 6.2

72.4 + 7.9

hours, after intravenous 0.1 unit/kg of insulin,

administration

of either 25 g of glucose, 1 g of glycodiazine*,

or 5000 IU of heparin.

The slope of the glucose disappearance tration

when plotted

appearance

1 S.D.

as a semilogarithmic

curve after intravenous function

represents

glucose adminis-

the rate of glucose dis-

in %/minz3.

Since lipolysis

continues

centrifuge

(+

specimens

were obtained

in vitro after heparin

4 “C) was used to separate

Statistical

analysis

and the estimation

the plasma of FFA

of the data was evaluated

administration,

a refrigerated

immediately

after the blood

was carried out without using Student’s

delay.

t-test24.

RESULTS

Oral glucose tolerance Table

2 shows that prediabetics

were practically

Fasting

had normal

glucose tolerance

and the results

similar to those of controls.

blood lip&

Tables 3 and 4 summarise lipid constituents

in the fasting

the results of the concentrations state,

and the incidence

of the various blood

of abnormally

elevated

values.

TABLE

2

RESULTS

OFORALGLUCOSETOLERANCETEST

Total number

Controls Prediabetics

81 100

Fasting Blood sugar (mg/lOO ml) after glucose by: blood sugar 7 hv (mg/lOO ml) 3 hr 14 hr

2 hr

71.4 f 9.8 76.3 + 11.2

70.1 f 9.6 80.9 & 12.3

136.2 f 18.1 144.0 & 17.5

110.6 f 118.4 f

* Redul(2-benzolsulfonamido-5-methoxyethoxy-pyrimidin-sodium), AG-Berlin.

20.3 21.4

84.5 f 12.8 90.7 & 14.4

Bayer-Leverkusen,

Atherosclerosis,

Schering

1972, 16: 51-60

3

i

* &

162

415 2.60

85.3 0.65

34.8

103.9

*

35.5

577

&

196

96.1 31.1

25.6 38.5 0.077

*

90

131 & 213 & 0.914 *

i

240

&

*

i

*

495.0 3.22

155.5

651.0

44.83” 45.5 0.09698

34.80”

134.9” 44.838

i f

84.4a 0.47a

_C 28.40

& 104.78

152.4 & 216.4 + 1.063 +

230.5

107.0

400.0

potential

Prediabetics

1 s.D.)

8 Significant as compared with controls. b Significant as compared with potentially diabetic subjects.

-I-

(mg/lOO ml) PI; (rng/lOO ml) C/P Total lipoproteins (mg/lOO ml) Alpha-lipoproteins (mg/lOO ml) Beta-lipoproteins

CllO~:CEL_rS

FFA (pequiv./l) TG (mg/lOO ml) Cholesterol total

Controls

FASTINGBLOODLIPIDCONCENTR.~TI~NS(MEAN

TABLE

& +

=

586.0 3.48

172.0

758 38.99

& 106.96b + 0.78”

&

& 127.2b

0.1148

26.70b 37.00a

44.8Ob

& 133.28 47.22b

&

chemical

1.095 *

168.8 237.6

261.2

129.0

433.0

latent

651.0 3.99

171.0

823

diabetic

&

55.5

202Sb

+ 177.6” * 1.22”

&

f

46.2Oh 48.00” 0.107&

58.90b

+ 168.2& i 51.48”

178.5 + 249.0 & 1.096 +

273.0

140.0

479.0

Chemically

subjects

LIPID METABOLISM

TABLE

55

IN PREDIABETICS

4

INCIDENCE

OF ABNORMAL

VALUESa

OF FASTING

BLOOD

Prediabetics

LIPIDS

Chemically diabetic subjects

potential

___ latent chemical

total esters

35.2 16.9 28.2 23.9

y0 % % y0

44.8 41.4 37.9 27.6

y0 y0 % %

52.4 38.1 54.8 38.1

7’ % “/u y0

:; Total lipoproteins Beta-lipoproteins B/A

53.5 9.8 9.8 16.9 9.8

y0 y0 y0 y0

62.1 6.9 44.8 37.9 27.6

y0 y0 y0 y0

64.3 21.4 57.1 50.0 40.5

“/ “/: y/; y0

FFA TG Cholesterol Cholesterol

8 Higher than the upper limit of the range in controls (Mean +

2 S.D.).

Intravenous glucose test The glucose disappearance was significantly

rate was normal in potentially

slower in diabetic

patients.

diabetic

subjects

and

The mean values were 1.48 and Q.65%/

min, respectively. At zero time, controls,

378 f

diabetics.

the average

level of plasma

110.6 ,uequiv./l in potential

The response

of FFA

FFA

was 209 & 82.3 ,uequiv./l in

diabetics

in diabetics

and 453 +

was characterised

normal initial drop, a delayed nadir, and a slow secondary diabetics, betics.

the response

was intermediate

between

138.2 pequiv./l in

by a significant

sub-

rise (Fig. 1). In potential

that of controls

and that of dia-

It is well to stress that during the period between 40 and 60 min after glucose

administration, subjects

the level of FFA

investigated,

was still declining

in all the potentially

whereas in all control individuals

diabetic

the level was rising.

Intravenoau insulin test The hypoglycaemic diabetic

subjects

effect

of insulin

and in asymptomatic

was within

diabetic

normal

patients,

limits

in potentially

The maximum

drop occur-

red at 30 min and was 51 o/oand 42 o/orespectively. Before

administration

of insulin the average level of plasma

104.8 pequiv./l in controls,

436 f

138.1 ,uequiv./l in diabetics.

The antilipolytic

in diabetic

patients;

subjects,

and the subsequent

the response

FFA

was 266 f

diabetics

and 353 &

effect of insulin was evidently

the initial drop of FFA was markedly

the nadir was delayed, diabetic

136.5 pequiv./l in potential

less than that of controls,

rise was slow and gradual.

approximated

that

abnormal

of diabetic

In potentially

patients

(Fig.

2.)

Intravenous glycodiazine test Changes MADISONz5,

in blood

sugar

level

verified

using 1 g sodium tolbutamide

the

instead.

criteria

given

In controls,

by

UNGER

potentially

Atherosclerosis,

AND

diabetic

1972, 16: 51-60

56

M. N. MIKHAIL

et al.

-60 -70

. 10203040f4@

(bknt

SE) uu

m m’n.

Fig. 1. Effect of i.v. glucose on the level of FFA. a--_ci: controls; Lk - -- A: potential diabetics; 0 - ~ - () : diabetics; A, 0: significantly different from controls; ( ): number of subjects.

-60

(Mrm

. . . . . W10304oB w

t

S.El

lpo

Fig. 2. Effect of insulin administration Alherosclerosis,

1972, 16: 51-60

180 nnn on the level of FFA.

For explanation

of symbols, see Fig. 1

LIPID METABOLISM IN PREDIABETICS

lo2030

45

60

Fig. 3. Effect of glycodiazine Fig. 1.

120 administration

57

lOOmin

on the level of FFA.

For explanation

of symbols, see

subjects and in diabetic patients the mean o/odrop of blood sugar 30 min after glycodiazine administration was 35 %, 31 o/oand 13 o/orespectively. 482 f

The average pretest level of plasma FFA was 235 f 98.8 pequiv./l in controls, 156.3 bequiv.11 in potential diabetics and 399 f 132.6 ,uequiv./l in diabetics.

After glycodiazine administration plasma FFA showed a response which was quite similar to that following insulin administration in potentially diabetic subjects and diabetic patients (Fig. 3).

1Dmm

60

la

160ml”

Fig. 4. Effect of i.v. heparin (5000 units) on the level of FFA. Fig. 1.

For explanation

Atherosclerosis,

of symbols,

see

1972, 16: 51-60

58

et al.

M. N. MIKHAIL

Intravenous

he$arin test

No change in the level of blood sugar was observed after heparin administration in controls,

potentially

diabetic

subjects

and diabetics.

redin the level of FFA which was markedly heparin was 286%, significantly

191 “/band 169%

660 +

The noticeable

diabetics

occur-

(Fig. 4). The latter two values were

The corresponding

two values were also significantly

change

The mean “;Orise 15 min after

above the zero level was 804 f

116.6 pequiv./l in potential

The latter

respectively

lower than that of controls.

plasma FFA concentration

elevated.

actual

increase

in the

138.3 pequiv./l in controls,

and 558 & 127.9 ,uequiv./l in diabetics. lower than that of controls.

DISCUSSION

In the fasting state, elevation to increased

mobilization

could possibly

of serum FFA concentration

could be attributed

from fat depots”, while that of TG, PL, and cholesterol

be due to increased

creased serum cholesterol

availablility

of fatty

level is mostly considered

esters

acids to the liverz6927. In-

to denote its decreased degrada-

tionss. A positive relation was found between the stage of the diabetic state (potential, latent

chemical,

and chemical)

In the present

and the degree of abnormality

work, our interest

has been mainly

blood lipids which have been demonstrated state, where there is no demonstrable prednisone

administration.

diabetic subjects action

The significant

Increased

activity

FFA-releasing

intolerance

even after

increase of FFA observed in the potentially resistant

of a hormone-sensitive

substances

of

early stage of the diabetic

marker of carbohydrate

suggests that adipose tissue is relatively

of insulinas.

such circulating

in a rather

in blood lipids.

focussed on the changes

to the antilipolytic

lipase, attributable

to

as growth hormone and glucocorticoidsa0Ji

could also be partly responsible. The significant atherogenic

elevation

of C/P and B/A ratios, which are among the accepted

indices, suggests increased liability

stage of the diabetic

The results of the intravenous levels of blood lipids. Moreover, ity of lipid metabolism administered potentially

diabetic

resulted subjects

these tests proved to unmask the existing

disappearance

diabetic

subjects.

Insulin,

abnormal-

both exogenously

secreted and released, after either glucose or glycodiin practically

the same

and diabetic patients.

sible are: relative insensitivity a decreased

at this early

tests confirm the data deduced from the fasting

in potentially

and endogenously

azine administration

to develop atherosclerosis

state.

abnormal

The probable

of adipose tissue to the antilipolytic

rate of circulating

FFA

response

mechanisms

in

respon-

action of insulinsg,

insulinaa~aa, and a defective

catechol-

amine response34J5. In spite of the acute elevation ministration, by SCHALCH heparinate, Atherosclerosis,

of plasma

the blood sugar level was unchanged. AND

subcutaneously

1972, 16: 51-60

after intravenous

heparin

ad-

Similar findings have been reported

et al. 37. Moreover,

long acting calcium

in a dose of 25,000 IU,

12 hourly for 5 days,

and by RUTSTEIN

KIPNI+

administered

FFA

LIPID METABOLISM

IN PREDIABETICS

59

produced a more sustained elevation of plasma FFA while the blood sugar level remained unchangedss. Elevation of plasma FFA has been suggested by RANDLE AND

KIPNIs~~

noticed

by

nificantly a fatty

to be

associated

with

SCHALCH AND KIPNIS different

from

control

impaired

that values

when

meal or 15 min after intravenous The subnormal

betic

subjects

these

subjects.

elevation

suggests

that

of FFA

glucose

the glucose

measured

following

However, rate

3 hours after

it was

was not

the ingestion

sigof

of heparin.

heparin

lipoprotein

tolerance.

disappearance

administration

post-heparin

et al.5 and SCHALCH

injection

lipase

in potentially

activity

is decreased

diain

REFERENCES 1 CAMERINI-DAVALOS, R. A., Prevention of diabetes mellitus, Med. Clin. N. Anaer., 1965,49: 865. 2 JAKOBSON, T., A. KAHANPAA AND E. A. NIKKILA, Serum lipids and glucose tolerance in subjects with family history of diabetes mellitus, Acta Med. Scand., 1965, 178: 181. 3 KALLIO, V., Fat loading test in males with diabetic heredity as compared to controls, diabetics and coronary patients, Acta Med. Stand., 1967, Suppl., 467. 4 LAURELL, S., Plasma free fatty acids in diabetic acidosis and starvation, Scand. J. Clin. Lab. Invest., 1956, 8: 81. s RANDLE, P. J., P. B. GARLAND, C. N. HALES AND E. A. NEWSHOLME, Glucose fatty acid cycle. Its role in insulin sensitivity and metabolic disturbances of diabetes mellitus, Lancet, 1963, 1:

785. 6 NEW,

M. I., T. N. ROBERTS, E. L. BIERX~ANAND G. G. READER, Significance of blood lipid alterations in diabetes mellitus, Diabetes, 1963, 12: 208. 7 ALBRINK, M. J., P. H. LAVIETES AND E. B. MAN, Vascular disease and serum lipids in diabetes mellitus. Observation over 30 years (1931-1961), Ann. Intern. Med., 1963, 58: 305. 8 JONSSON, A., J. GOA, S. E. FAGERBERG AND B. HOOD, Seromucoid fractions, serum proteins and lipids in diabetes mellitus, Acta Med. &and., 1963, 174: 701. 9 OSTMAN, J,, Studies in vitro on fatty acid metabolism of human subcutaneous adipose tissue in diabetes mellitus, Acta Med. Stand., 1965, 177: 639. 10 STEINBERG, A. G., Heredity in diabetes mellitus, Diabetes, 1961, 10: 269. 11 CAMERINI-DAVALOS, R. A., J. B. CAULFIELD, S. B. REES, 0. LOZANO-CASTANEDA, S. MALDJIAN AND A. MARBLE, Preliminary observations on subjects with prediabetes, Diabetes, 1963,12: 508. 12 WORLD HEALTH ORGANIZATION, Diabetes Mellitus (WHO Report, No. 310), 1965, p. 7. 13 FAJANS, S. S. AND J. W. CONN, An approach to the prediction of diabetes mellitus by modification of glucose tolerance test with cortisone, Diabetes, 1954, 3: 296. 14 DUNCOMBE, W. G., The calorimetric micro-determination of nonesterified fatty acids in plasma, Biochem. J., 1963, 88: 7. 15 VAN HANDEL, E. AND D. B. ZILVERSMIT, Micromethod for the direct determination of serum triglycerides, J. Lab. Clin. Med., 1957, 50: 152. 16 BLOOR, W. R., H. F. PELKAN AND D. M. ALLEN, Determination of fatty acids and cholesterol in small amounts of blood plasma, J. Biol. Chem., 1922, 52: 191. 17 KELSEY, F. E., Determination of cholesterol, J. Biol. Chew, 1939, 127: 15. 18 KING, E. J. AND I. D. P. WOOTTON, Microanalysis in Medical Biochemistry, 3rd edition, Churchill, London, 1959. 19 SWAHN, B., Estimation of serum lipoproteins, Stand. J. Gin. Lab. Invest., 1952, 4: 98. 20 LEVINSON, S. A. AND R. P. MACFATE, Clinical Laboratory Diagnosis, 6th edition, Henry Kimpton, London, 1962. 21 CHAPIN, M. A., The distribution of lipid and phospholipid in paper electrophoresis of normal serum lipoprotein, J. Lab. Clin. Med., 1956, 47: 386. 22 ASATOOR, A. AND E. J. KING, Simplified calorimetric blood sugar method, Biochem. J., 1954, 56: xliv. 23 SILVERSTONE, F. A., M. BRANDFONBRENER, N. W. SHOCK AND M. J. YIENGST, Age differences in the intravenous glucose tolerance tests and the response to insulin, J, Clin. Invest., 1957, 36:

504. 24 YOUDEN, W. J.. Statistical Methods for Chemists. Wiley,

New York,

N.Y.,

1951.

Atherosclerosis,

1972, 16: 51-60

M. N. MIKHAIL et d.

60

25 UNGER, R. M. AND L. MADISON, Comparison of response to intravenous

administrated sod. tolbutamide in mild diabetics and non-diabetic subjects, J. Clin. Invest., 1958, 37: 627. 26 FREDRICKSON, D. S. AND R. S. GORDON, JR., Transport of fatty acids, P$&oZ. Rev., 1958, 38: 585. 27 SIPERSTEIN, hf., In: R. H. WILLIAMS (Ed.), Diabetes, Hoeber, New York, N.Y., 1960. 28 WONG, R. K. L. AND J. T. VAN BRUGGEN, Lipid metabolism in diabetic rat. Cholesterol turnover studies, J. Bid. Chew., 1960, 235: 30. 38 COLWELL, J. A. AND A. LEIN, Diminished insulin response to hyperglycemia in prediabetes and diabetes, Diabetes, 1967, 16: 560. 3” CHERNICK, S. S. AND R. 0. Scow, Hormonal control of protein and fat metabolism in pancreatomized rat, Hecent Prop. Harm. Hes., 1960, 16: 497. 31 HOUSSAY, B., Hormonal factors of diabetic ketosis, Diabetes, 1963, 12: 481. 3* BUTTERFIELD, W. J. H., C. J. GARRATT AND M. J. WICHELOW, Peripheral hormone action. Studies on the clearance and effect of (1131) iodo-insulin in the peripheral tissues of normal, acromegalic and diabetic subjects, Clin. Sci., 1963, 24: 331. 33 STIMMLER, L., Disappearance of immunoreactive insulin (IRI) in normal and adult onset diabetic subjects, Diabetes, 1967, 16: 652. 34 BARRETO, H. P. B. AND I,. RECANT, Tolbutamidc studies in prediabetes, z-lnn. _\‘.Y. dcrcd. Sci., 1959, 82: 560. 35 DOLINGER, R. E., S. R. SHAKE AND C. KIRKPATRICK, Factors influencing the late secondary rise in plasma free fatty acid following glucose loading, J. Lab. Clin. Med., 1961, 58: 801. 36 SCHALCH, 1). S. AND D. 31. KIPNIS, Abnormalities in carbohydrate tolerance associated with elevated plasma nonesterified fatty acids, J. Clin. Invest., 1965, 44: 2010. 37 RUTSTEIN, D. 1). , W. P. CASTELLI APEDR. J. NJCKERSON, Heparin and human lipid metabolism, Lancet, 1969, 1: 1003. 38 GHANEM, M. H., S. TAWFIK, F. K. GCIRGIS AXD M. EL-Sawu, ApprCciation de l’effet de l’hiparine sous-cutanke sur la coagulabilitb et les lipides sanguins chez les diabktiques, Sem. I‘he’r., 1971, 47: 473.

Atherosclerosis,

1972, 16: 51-60