Israel Medical Association Journal

Background: Oral contraceptive users are at increased risk for both arterial and venous thrombosis, some of which can be fatal. Studies are consistent with the existence of a synergism between cigarette smoking and OC[1] use in the pathogenesis of myocardial infarction in young women.

Objectives: To study the relationship between OC use, cigarette smoking and other cardiovascular risk factors among young women.

Methods: A systematic sample of military personnel, upon discharge from service in the Israel Defense Forces, was asked to complete a research questionnaire. Body weight and height were measured and body mass index computed.

Results: Overall, 16,258 questionnaires were collected and analyzed during this 20 year study. There was a gradual, significant increase in OC use until the mid-1980s, from approximately 45% to 60% (P < 0.001), followed by steady rates of 58–64% since then. In contrast, the rates of smoking decreased significantly in the mid-1980s, from approximately 42% to a nadir of 22% in 1991. Since then, the rate of smoking has increased slowly but steadily, to reach a level of 35% in 1999. The OC users were more often of western (Ashkenazi) origin and came from families with more education and fewer siblings. They were more often smokers than non-OC users, and started smoking at a younger age. They had significantly lower BMI[2] than non-users. OC use was nearly identical in groups with or without multiple cardiovascular risk factors (smoking, obesity, family history).

Conclusions: Smoking and OC use are strongly associated. Other cardiovascular risk factors (smoking, obesity, family history) do not prevent OC users from smoking or smokers to use OC. We suggest that primary care physicians discourage smoking among adolescent females who wish to start using OC. A thorough medical history should be obtained to recognize all risk factors for cardiovascular disease and to provide for appropriate contraception counseling.

Background: Previous studies have shown a low prevalence of diabetes and other cardiovascular risk factors among Bedouins living in the Negev Desert. New evidence suggests that diabetes is becoming highly prevalent.

Objectives: To estimate the prevalence of diabetes in the town of Rahat, describe the cardiovascular risk factor profile and therapeutic modalities for diabetes and related conditions in this population, and compare these findings with those in the Jewish population.

Methods: A complete record review of all known diabetic individuals aged 35 and older registered at the Rahat Clinic (Clalit Health Services) was carried out by a trained nurse and a research assistant. Information on demographic, anthropometric and clinical characteristics was abstracted. Data on prescribed hypoglycemic agents and other medications were also obtained.

Results: Of the 316 known diabetic patients in the clinic, complete data were available for 271 (85.8 %). The prevalence of known diabetes was 7.3% in males and 9.9% in females. Females had a significantly higher body mass index than males (30.9 vs. 29, P < 0.002), but lower levels of HBA1c and microalbuminuria. Oral hypoglycemic medications were taken by 69% of women and 76% of men, and insulin by 19% of women and 15% of men.

Conclusions: Compared with data on Jewish diabetic patients in the Negev and Israel, the overall prevalence of diabetes in the population of Rahat is higher, but their cardiovascular risk profile is better, except for obesity. These findings support the hypothesis that diabetes and obesity have become major public health problems among Bedouins.
 

Background: Obesity is among the well-established risk factors for cardiovascular morbidity and mortality. However, the exact mechanisms are not well understood. Low concentrations of vitamins (fat soluble antioxidants and B vitamins) are linked to accelerated atherosclerosis through increased oxidative stress and homocysteine.

Objective: To compare plasma antioxidant vitamins (carotenoids and vitamin E), B vitamins (folic acid and B12) and homocysteine – all linked to increased cardiovascular morbidity – between patients with severe obesity and lean control subjects.

Methods: We investigated plasma carotenoids, vitamin E, folic acid, B12, and homocysteine in 25 obese patients and their age-matched controls (body mass index 38 ± 3 vs. 21 ± 2 kg/m²), respectively), related to BMI[1] and plasma insulin.

Results: Patients with obesity had normal B vitamins and a non-significant decrease in plasma homocysteine as compared to controls (9.4 ± 2.6 vs. 11.4 ± 4.8 mmol/L, P = 0.07). There was a significant decrease in both plasma carotenoids and vitamin E (0.69 ± 0.32 vs. 1.25 ± 0.72 and 24 ± 10 vs. 33 ± 14 mg/ml, respectively; P < 0.01). Both vitamins were inversely related to BMI and plasma insulin, which was significantly increased in patients with obesity (22 ± 21 vs. 6 ± 2 mU/ml, P < 0.01).

Conclusions: Obese patients with BMI above 35 kg/m² show low plasma antioxidants (carotenoids and vitamin E). This may result in increased oxidative stress and consequently enhanced atherosclerosis in these patients.

Background: Multiple factors are involved in the pathogenesis of hypertension in the obese individual.

Objective: To evaluate the role of a decrease in sympathetically mediated thermogenesis and the effect of the correlation between the plasma leptin and daily urinary nitric oxide levels on obesity-related hypertension.

Methods: We evaluated three groups: 25 obese hypertensive patients (age 45.7±1.37 years, body mass index 34.2±1.35 kg/m², systolic/diastolic blood pressure 155±2.9/105±1.3, mean arterial pressure 122±1.50 mmHg); 21 obese normotensive patients (age 39.6±1.72, BMI[1] 31.3±0.76, SBP/DBP[2] 124±2.1/85.4±1.8, MAP[3] 98.2±1.80); and 17 lean normotensive subjects (age 38.1±2.16, BMI 22.1±0.28, SBP/DBP 117±1.7/76.8±1.5, MAP 90.1±1.50). We determined basal resting metabolic rates, plasma insulin (radioimmunoassay), norepinephrine (high performance liquid chromatography) in all subjects. Thereafter, 14 obese hypertensives underwent a weight reduction diet. At weeks 6 (n=14) and 14 (n=10) of the diet the above determinations were repeated. Plasma leptin (enzyme-linked immunosorbent assay) and UNOx[4] (spectrophotometry) were assayed in 17 obese hypertensives and 17 obese normotensives, and in 19 obese hypertensives versus 11 obese normotensives, respectively.

Results: Obese hypertensive patients had significantly higher basal RMR[5] and plasma NE[6] levels. Insulin levels were lower in the lean group, with no difference between the hypertensive and normotensive obese groups. At weeks 6 and 14, BMI was significantly lower, as were insulin and NE levels. RMR decreased to values of normotensive subjects. MAP normalized but remained significantly higher than that of obese normotensives. Leptin blood levels and the leptin/UNOx ratio were significantly higher in the obese hypertensive compared to the obese normotensive patients. Both these parameters were strongly correlated to BMI, MAP⁵, RMR, and plasma NE and insulin .Obese hypertensive patients excreted less urinary NO metabolites. A strong correlation was found between MAP and the leptin/UNOx ratio.  

Conclusions: A reduction of sympathetically mediated thermogenesis, as reflected by RMR, results in normalization of obesity-related hypertension. In contrast, insulin does not seem to play a major role in the pathogenesis of hypertension associated with obesity. Increased leptin levels in conjunction with decreased NO production in the presence of enhanced sympathetic activity may contribute to blood pressure elevation in the obese.

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[1] BMI = body mass index

[2] SBP/DBP = systolic blood pressure/diastolic blood pressure

[3] MAP = mean arterial pressure

[4] UNOx = urinary nitric oxide

[5] RMR – resting metabolic rate

[6] NE = norepinephrine

Background: Dyslipidemia and obesity serve as risk factors for the development of atherosclerotic cardiovascular disease. Fasting is sometimes recommended for treating these conditions. This study was undertaken to try to resolve conflicting results reported in the literature.

Objectives: To study the effect of fasting (0 calories, with free intake of fluids) for 3-5 days on plasma concentration of triglyceride, cholesterol and apolipoprotein B.

Methods: Physicians, about to begin a hunger strike, were divided into four groups: normolipidemic non-obese men (group 1), two moderately obese men and two men with type IV hyperlipidemia (group 2), healthy non-obese women (group 3), and healthy non-obese women on oral contraceptives (group 4). Adherence to fasting was monitored daily by detailed interviews, loss of weight, drop in plasma glucose, presence of ketonuria, progressive rise in serum creatinine and uric acid, and decrease in plasma pH. We monitored their serum glucose, electrolytes, liver function, lipids, lipoproteins and apolipoprotein B on days 0, 3, and 5.

Results: Physicians who adhered to complete fasting lost more than 1.5% of their body weight after 3 days of fasting (n=12), and more than 3.2% at 5 days (n=5). All non-obese normolipidemic males and females (groups 1 and 3) showed an increase in plasma triglyceride (by 28-162%) and very low density lipoprotein cholesterol (by 22-316%) after 3 days of fasting. The obese and hyperlipidemic men (group 2) showed a decrease of 17-63% in their VLDL cholesterol, and the women on oral contraceptives (group 4) showed a 20% decrease in their plasma triglyceride on day 3. Low density lipoprotein cholesterol increased by 13% in group 2, decreased by 7.3% in group 4, and remained unchanged in group 1 and 3. Apolipoprotein B level correlated well with LDL cholesterol in all groups. High density lipoprotein cholesterol changes were inconsistent.

Conclusions: These results help to explain and reconcile previous published reports. The metabolic background of the individual together with the amount of energy consumed affect the behavior of plasma lipids and lipoproteins levels during fasting.

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VLDL= very low density lipoprotein

LDL= low density lipoprotein
 

Background: Obesity, a common condition in developed countries, is recognized as a threat to health.

Objectives: To describe the distribution of weight in pregnant women and evaluate the influence of obesity on pregnancy outcome in a high parity northern Israeli population.

Methods: The study included 887 women who gave birth in the Western Galilee Medical Center during the period August to November 1995. The patients were classified as underweight, normal weight, overweight, or obese according to body mass index. Maternal demographic, obstetric, and perinatal variables were compared. A control group of 167 normal weight women were matched with the obese group for maternal age, parity, and gestational age.

Results: Obese mothers had a higher incidence of gestational diabetes and pregnancy-induced hypertension compared to normal weight mothers (5.4% vs. 1.8%, and 7.2% vs. 0.6% respectively, P<0.01), a higher rate of labor induction (20.4% vs. 10.2%, P<0.01), and a higher cesarean section rate (19.6% vs.10.8%, P<0.05). There was also a significant difference in the prevalence of macrosomia in the offspring (16.8% vs. 8.4%, P<0.05).

Conclusion: Obese pregnant women are at high risk for complications during delivery and therefore need careful pre-conception and prenatal counseling, as well as perinatal management.