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Biomedical subjects

H Lithell

Publications and source records attributed to H Lithell.

At least 235 records · Page 13Linked to original sources

Diet therapy for poorly controlled type 2 (non-insulin-dependent) diabetes mellitus.

Poorly controlled type 2 diabetes represents a major therapeutic problem. A classification of the disease, based on body weight and presence or absence of adequate insulin-secretion capacity, may be helpful in the choice of correct treatment. Calorie reduction is the most important therapeutic intervention in overweight patients. In the diabetic diet digestible carbohydrates should comprise at least 50 energy%, while the fat content should be reduced below 30 energy%. Controlled clinical studies show that the blood glucose control can be improved and the urinary glucose excretion be diminished by addition of dietary fibre. In obese type 2 diabetics supplemented fasting may be useful to achieve a rapid weight loss and an improved metabolic control. Although our knowledge with regard to the patho-physiology of type 2 diabetes and the effects of dietary treatment has increased during recent years, several important questions remain unanswered. Also there is a great need for education and training programmes to achieve improved compliance to the dietary advice given.

Blood Glucose↗

High muscle lipoprotein lipase activity in thyrotoxic patients.

Serum lipoprotein metabolism was studied in 7 women before and after treatment for thyrotoxicosis. Of the lipoprotein lipids, the triglyceride concentration in the low density lipoproteins (LDL) (P less than 0.01) and the cholesterol concentration in both LDL (P less than 0.01) and the high density lipoproteins (HDL) (P less than 0.05) increased significantly during treatment. These changes were accompanied by increases in apolipoprotein B (P less than 0.01) and A-I (P less than 0.05) concentrations in serum. Muscle lipoprotein lipase activity (LPLA) was increased in the thyrotoxic state by 46% (P less than 0.05) compared with the value after the patients had been rendered euthyroid, but adipose tissue LPLA was only 8% higher (ns) in the former state. The capacity for removal of exogenous fat, as determined by the fractional elimination rate (K2) at an iv fat tolerance test, was 23% higher in the thyrotoxic than in the euthyroid state (ns). It is suggested that the increase in muscle LPLA in the thyrotoxic state may be due to enhanced sensitivity to catecholamines. This may contribute to the increased capacity for plasma triglyceride turnover in thyrotoxicosis.

Adipose Tissue↗

Changes in lipoprotein metabolism during a supplemented fast and an ensuing vegetarian diet period.

The effect on lipoprotein metabolism of a 2-week modified fast and an immediately ensuing 3-week period on a vegetarian diet was studied under metabolic ward conditions in 21 non-obese female and 6 male patients. The very low calorie diet induced reductions of the cholesterol concentration in all serum lipoprotein classes. In the female patients, who were all normolipoproteinaemic, the triglycerides in serum showed a slight increase during the fast, reflecting small changes in very low (VLDL) and low density lipoprotein triglycerides. This may probably be explained partly by simultaneous significant reductions of both the adipose tissue and skeletal muscle tissue lipoprotein lipase activities (LPLA). In contrast, in the male patients who had a higher VLDL level at admission, the VLDL triglycerides decreased without significant changes of high density lipoprotein (HDL) cholesterol and of LPLA in muscle. The female patients, whose weights were stable during the vegetarian diet, ended up with a lower HDL cholesterol than at the start of the trial. This effect was probably partly due to the high content of polyunsaturated fatty acids in the vegetarian diet. It is concluded that the changes of lipoprotein metabolism during supplemented fasting are quantitatively and qualitatively different in several respects in females and males.

Adult↗

Glucose metabolism during long-term treatment with prazosin.

The metabolic effects of the alpha 1-adrenoceptor blocking drug prazosin was evaluated in 8 premenopausal women undergoing treatment for essential hypertension. Intravenous glucose tolerance (IVGTT) and the early insulin response was studied before treatment, after 1 and 12 months and 3 weeks after cessation of drug treatment. The k-value for the glucose disappearance decreased from 2.9 to 2.0 after 1 month. No further change occurred after 12 months. After cessation of the drug the k-value returned to the pre-treatment level. The decreased glucose tolerance was accompanied by a decrease in the early insulin response. It is suggested that the reversible decrease in glucose tolerance is due to an inhibition of the early insulin response, mediated by the increase in circulating catecholamines reported during prazosin treatment.

Adolescent↗

Non-response of muscle capillary density and lipoprotein-lipase activity to regular training in diabetic patients.

Ten obese women with normal glucose tolerance, 10 obese patients with sulphonylurea-treated non-insulin-dependent diabetes (NIDD) and 11 patients with insulin-dependent diabetes (IDD; treated for 3-31 yr) took part in a 10-week programme of physical training in 50-min sessions, 2-3 times a week. As a result of training, maximal oxygen uptake increased significantly by about 18, 13 and 8% in the 3 groups, respectively, and citrate synthase in muscle increased significantly by 27-42%. The lipoprotein-lipase activity in muscle tissue (sampled by a needle-biopsy technique from the lateral vastus muscle) did not change. The number of capillaries/fibre in muscle tissue increased. This was accompanied by an increase in muscle fibre area, resulting in an unchanged number of capillaries/mm2. This may explain why the lipoprotein-lipase activity was unaltered. The latter activity in the group with IDD was lower than was predicted from the number of capillaries/mm2. This number was in fact larger than in the obese and NIDD groups. These results indicate that the increase in capillary density and lipoprotein-lipase activity that occurs in healthy young individuals as an effect of endurance training does not take place in obese, NIDD and IDD patients.

Adult↗

Is muscle lipoprotein lipase inactivated by ordinary amounts of dietary carbohydrates?

Lipoprotein metabolism was investigated in 12 patients, healthy except for renal stone disease, who received a high-protein experimental diet for 2 weeks under metabolic ward conditions. The results were compared with those after 2 weeks on a control diet of ordinary composition. The patients were randomly allocated to begin with the control or experimental diet. The energy contributions from protein, carbohydrate and fat were 12, 48 and 41 per cent in the control diet and 29, 31 and 41 per cent in the experimental diet, respectively. Fasting concentrations of very-low-density lipoprotein (VLDL) triglycerides and cholesterol were lower with the high-protein than with the control diet (0.69 vs 1.4 mmol/l, P less than 0.0001, and 0.33 vs 0.47 mmol/l P less than 0.01, respectively). High-density lipoprotein cholesterol tended to be higher (0.05 less than P less than 0.10) with the high-protein diet. Lipoprotein-lipase (LPL) activity in skeletal muscle and the fractional catabolic rate constant of an intravenous fat tolerance test were higher with the high-protein than with the control diet (38 vs 21 mU/l, P less than 0.01, and 5.1 vs 3.6 mU/l, P less than 0.001, respectively). Neither fasting blood glucose, intravenous glucose tolerance nor insulin concentrations differed between the two dietary periods. These findings indicate that an 'ordinary' intake of refined carbohydrates has an inhibitory effect on the muscle LPL activity, thereby increasing the VLDL level and slightly decreasing the level of high-density lipoproteins, which may be of relevance for the atherosclerotic process.

Adult↗

Effects of an increased content of cereal fibre in the diet of Type 2 (non-insulin-dependent) diabetic patients.

The metabolic effects of an increased dietary content of cereal fibre were studied in 14 Type 2 diabetic subjects. They were given two isoenergetic diets in randomised order during two consecutive 3-week periods. A diabetic diet, containing 18.9 g dietary fibre/6.7 MJ (1600 kcal), was compared with a diet of identical composition except for an increased content of cereal fibre (42.4 g dietary fibre/6.7 MJ). The mean blood glucose level and the urinary glucose excretion were significantly lower in patients on the cereal-fibre-rich diet, while the serum insulin concentrations were similar. The mean blood glucose level was significantly reduced at 0700 h by 6% (p less than 0.05) and at 1100 h by 13% (p less than 0.01) on the high-fibre diet. Consequently the insulin/glucose ratio was higher (33%, p less than 0.02) in patients on the fibre-enriched diet. There were only minor differences with regard to the serum lipoprotein concentrations. The lipoprotein lipase activities were similar in the two dietary groups. The reduction of blood glucose concentrations together with unchanged serum insulin concentrations is compatible with improved peripheral insulin sensitivity.

Aged↗

Further increase in high density lipoprotein in trained males after enhanced training.

Eight well-trained males were studied before, during and after 6 months of a progressively increased amount of endurance training in order to elucidate the effects on the apoproteins and apolipoproteins. Initially high HDL-cholesterol levels were revealed (1.62 +/- 0.15 mmol X 1(-1), mean +/- SE.). After a transient but not significant, slight decline at the onset of the increased training program (1.57 +/- 0.06 mmol X 1(-1] HDL-cholesterol increased gradually to the end of the training period (1.92 +/- 0.12 mmol X 1(-1). There was an increased aerobic capacity as judged by maximal oxygen uptake and by lactate concentration during standardized submaximal work. However, at the end of the training period, a levelling off in maximal oxygen uptake was revealed, while HDL-cholesterol was still increasing. The present data demonstrate that HDL can be influenced by training at all levels of aerobic capacity.

Adult↗

Improved metabolic control after supplemented fasting in overweight type II diabetic patients.

Twenty obese type II diabetes patients were treated in a metabolic ward during 4 weeks with a very low calorie regimen (200 kcal/day). They were given dietary advice and reexamined 3 months after discharge. Mean body weight decreased by 10 kg during fasting, blood glucose was normalized, urinary glucose disappeared and the K-value at i.v. glucose tolerance test increased. Fasting serum insulin concentrations decreased by 54%. Serum triglycerides (TG) decreased by 65%, serum cholesterol (Chol) by 28% and high density lipoprotein (HDL) Chol by 14%. Three months later, only serum TG remained significantly decreased (-47%) while HDL Chol was significantly higher than on admission (+11%). Fasting blood glucose remained significantly lower (-25%) with a low urinary glucose excretion. Supplemented fasting appears to be a safe and useful tool in the treatment of obese type II diabetics. It causes, at least during a limited follow-up period, a significant improvement in glucose control and lipoprotein metabolism in spite of a concomitant reduction of the antidiabetic medication.

Adult↗

Serum lipoprotein and apolipoprotein concentrations in patients with hyperthyroidism and the effect of treatment with carbimazole.

Forty patients, 32 women and 8 men, with hyperthyroidism were investigated concerning serum lipoprotein lipid and apolipoprotein concentrations before, during and after treatment with carbimazole to euthyroidism. During the hyperthyroid condition the patients had significantly lower serum concentrations of low density lipoprotein (LDL) and high density lipoprotein (HDL) cholesterol. The serum lipoprotein triglyceride concentrations were within the normal ranges. During treatment to euthyroidism the low serum concentrations of LDL and HDL cholesterol increased to normal values. LDL and HDL concentrations increased in the female patient group by 46 +/- 12 and 25 +/- 9% and in the male patient group by 50 +/- 12 and 19 +/- 11%, respectively. During treatment serum apolipoprotein B and A-I concentrations increased significantly in females by 58 +/- 9 and 18 +/- 5% and in males by 60 +/- 9 and 13 +/- 8%, respectively.

Adolescent↗

Effects of high intake of dietary animal protein on mineral metabolism and urinary supersaturation of calcium oxalate in renal stone formers.

The metabolic effects of a high protein diet (HPD) were studied in eight patients with idiopathic recurrent calcium oxalate stones. On the HPD there was a 35% increase in urinary calcium concomitant with increased excretion of cyclic AMP and hydroxyproline. These findings point to an enhanced resorption of bone, possibly secondary to increased renal loss of calcium. The urinary citrate decreased by 25% along with reduced serum standard bicarbonate and urinary pH. The high formation of acid metabolites might also have adverse effects on calcium balance and bone. Urinary oxalate excretion was not affected nor were there any significant changes in the calculated urinary supersaturation of calcium oxalate, if changes in urinary citrate, pH, sulphate, sodium, phosphate and volume were also considered. This study suggests that the possible negative influence on the propensity to form renal stones of a diet rich in animal protein is probably due to reduced urinary inhibitory activity.

Adult↗

Lipoproteins, lipoprotein lipase, and glycogen after prolonged physical activity.

The effect of strenuous exercise on lipoprotein level and composition as well as on lipoprotein lipase activity (LPLA) and glycogen stores in skeletal muscle was studied in 16 healthy young men after military field maneuvers. Body weight was reduced by 1 kg after the maneuvers and was gradually restored during a 5-day recovery phase. Glycogen levels were reduced by 50% and LPLA increased threefold immediately after the exercise, and neither were restored until 3-5 days of recovery. Serum triglycerides were decreased by about 50% after 1 day of recovery and the cholesterol concentration in high-density lipoproteins increased but only immediately after exercise. In contrast, the apolipoproteins A-I and A-II, the main protein constituents, were both decreased and remained so for 3-5 days. The results indicate that significant alterations of plasma lipoprotein level and composition as well as of muscle metabolism occur after prolonged physical exertion and that some changes are still evident after 5 days of recovery.

Adult↗

Unaltered lipoprotein and carbohydrate metabolism during treatment with contraceptive subdermal implants containing ST-1435.

Nine healthy, fertile women were treated for six months with subdermal contraceptive implants of two different sizes containing a potent progestogen, ST-1435. Lipoprotein cholesterol and triglyceride concentrations were not influenced by the treatment. Similarly, the main apolipoproteins in low- and high-density lipoproteins were not changed, which further supports the interpretation that the lipoprotein metabolism is not affected by this type of treatment. An oral glucose tolerance test (OGTT) including insulin determinations was performed in five of the volunteers with the largest implants. Blood glucose and insulin concentrations during the OGTT remained unchanged during treatment, indicating that the treatment with ST-1435 did not affect carbohydrate metabolism.

Adult↗

Pharmacodynamics of a contraceptive vaginal ring releasing norethindrone and estradiol: ovarian function, bleeding control and lipoprotein patterns.

A new contraceptive vaginal ring (CVR), releasing approximately 700 micrograms of norethindrone (NET) and approximately 140 micrograms of estradiol (E2) daily, was studied in eleven women for a total of 61 21-day cycles. Ovarian function, as judged by plasma progesterone (P) and E2 levels, and plasma NET levels were studied by weekly blood samples in 30 cycles. The lipoprotein pattern was studied before, after two and six months of treatment and one month after completed treatment. The CVR gave rise to stable plasma NET levels which however varied considerably between individuals. Signs of luteal activity/ovulation were encountered in 4/30 cycles, all in subjects with the lowest NET plasma levels. E2 levels above 250 pmol/l, indicating follicular activity, were encountered in 22/30 cycles. Breakthrough bleeding and spotting appeared in 40/61 cycles and in 12 per cent of the treatment days. Bleeding control was significantly better in the same subjects when using a CVR releasing levo-Norgestrel and E2. Serum and HDL cholesterol concentrations decreased significantly by 10-12 per cent during treatment. The ratios between apolipoproteins A-I and A-II on one hand and HDL cholesterol on the other increased significantly and the ratio apolipoprotein A-I:A-II decreased significantly, indicating a change in the lipoprotein composition. These changes are qualitatively similar but quantitatively not as pronounced as with the more extensively studied 1-Ng/E2 CVR. The difference in clinical performance and in the effects on the lipoprotein pattern between the presently studied CVR and the 1-Ng/E2 CVR is most likely the result of not using equipment doses of gestagen in the CVRs.

Adult↗

Lack of effect of a purified bran preparation in men with low HDL cholesterol.

In 21 men who had been on a lipid-lowering diet for several years, the serum triglyceride and cholesterol levels had become normal on that treatment. In spite of this they all had low levels of cholesterol in the high density lipoproteins (HDL). In an effort to normalize this they were given a purified concentrated bran product (FiberformR, 3.5 g) three times daily for 6 weeks. The cross-over study was double-blind, placebo-controlled, and with a wash-out period between the treatment periods. There were no statistically significant changes in body weight, serum triglycerides and cholesterol or HDL triglycerides and cholesterol in association with the bran treatment. It is concluded that wheat bran in moderately large doses that are convenient to take does not offer a therapeutic alternative for increasing subnormal HDL cholesterol levels in normocholesterolaemic men.

Cholesterol↗

The primary preventive study in Uppsala. Fatal and non-fatal myocardial infarction during a 10-year follow-up of a middle-aged male population with treatment of high-risk individuals.

A health survey of middle-aged men was carried out in 1970-73 in the municipality of Uppsala. Subjects with hypertension, hyperlipidaemia, reduced glucose tolerance, and smokers were invited to join various therapy groups. By 1980 this multifactorial intervention programme had thus been running for 10 years. This report describes the results of a follow-up undertaken to evaluate the efficacy of the programme. The annual rate of fatal myocardial infarction (MI) was lower among the participants (n = 2322) in the health examination as well as among participants and non-participants (n = 446) combined than among the male Swedish population of the same age (162 and 187 compared with 296 per 100 000 men, respectively). The annual rate of non-fatal MI among participants and non-participants combined was 295 per 100 000 men, which is lower than in other Swedish cities. In the hypertensive group (n = 126), six men had fatal and seven non-fatal MI. These 13 men had higher blood pressures (BPs) from the start than the other hypertensives. In addition, their BP reduction was smaller than in a control group randomly selected among the hypertensive subjects. In the hyperlipidaemic treatment group (n = 363) there were eight fatal and 10 non-fatal MIs. Nine of these events occurred in individuals who had dropped out from therapy. It is suggested that the low total mortality and the low rates of fatal and non-fatal MI in this middle-aged male population may be related to the multifactorial intervention programme, as the incidences were also low among the treated high-risk groups.

Age Factors↗