P. Strazzullo

Controlled trial of low calcium versus high calcium intake in mild hypertension

A controlled trial of the effect of low versus high calcium intake on blood pressure was performed in 15 patients with mild essential hypertension (supine blood pressure after a 1-month run-in period: 145.7 +/- 2.6/97.8 +/- 0.9 mmHg, mean +/- s.e.m.). After a 1-week baseline period on a standard calcium intake (900 mg/day, obtained by giving a 500-mg calcium tablet daily, in addition to a 400-mg calcium diet), the patients were randomly entered into a double-blind crossover study of 4-week low calcium intake (400 mg calcium diet plus two placebo tablets/day) and 4-week high calcium intake (1400 mg/day: 400-mg calcium diet plus two 500-mg calcium tablets/day). Compliance with the diets appeared to be satisfactory, based on the results of food record analysis. No significant blood pressure change was observed at the end of the low-compared to the high-calcium regimen. Serum ionized calcium was slightly, but not significantly lower, while 24-h urinary calcium excretion was significantly reduced during the low-calcium diet. No difference was found in urinary sodium and potassium excretion between the two study periods. We conclude that moderate modifications of oral calcium intake are not associated with changes in blood pressure within the time span of this study.

Prevalence of simple nodular goiter and Hashimoto's thyroiditis in current, previous, and never smokers in a geographical area with mild iodine deficiency.

Simple nodular goiter and Hashimotos thyroiditis are 2 frequent nonmalignant thyroid diseases. Tobacco smoking has detrimental effects on the endocrine system and in particular on thyroid function and morphology. The objective of this cross-sectional study, involving 1800 Caucasian adults from a geographical area with mild iodine deficiency, was to evaluate the relationship between tobacco smoking, smoking cessation, and the prevalence of simple nodular goiter and Hashimotos thyroiditis. Thyroid status was evaluated by ultrasonic exploration of the neck, measurement of FT3, FT4, TSH, antibodies against thyroid peroxidase and thyroglobulin, and urinary iodine excretion. The fine-needle aspiration biopsy of significant nodules was also performed. Smoking habits were evaluated by a specific questionnaire and the calculation of number of pack years. Both current and previous smokers showed an increased risk of simple nodular goiter compared to never smokers after adjustment for potential confounders and known goitrogen factors. Interestingly, the simple nodular goiter risk was similar for never smokers and for previous smokers declaring a time since cessation of smoking for more than 69 months. Smoking habit was not associated to an increased risk of Hashimotos thyroiditis.Smoking appears to be an independent risk factor for simple nodular goiter but not for Hashimotos thyroiditis in an area with mild iodine deficiency. A prolonged withdrawal of smoking dramatically reduces the risk of simple nodular goiter occurrence.

Antihypertensive and renal effects of acute and chronic therapy with a dihydropyridine Ca-antagonist in patients with different salt sensitivity.

We evaluated the effect of the dihydropyridine Ca-channel blocker nitrendipine on blood pressure (BP) and electrolyte urinary excretion after acute and chronic therapy in 33 patients with different NaCl sensitivity as assessed by a modification of the test of Grim and colleagues. Acute nitrendipine administration significantly reduced BP in the group as a whole, although the hypotensive effect was greater in patients with greater NaCl sensitivity; this difference was still evident after 1 month of chronic therapy. Furthermore, urinary sodium and calcium excretion significantly increased in the 3 h after nitrendipine administration during both acute and chronic therapy: these effects on electrolyte excretion were independent of the NaCl sensitivity of the subject.

Controlled study with a new sustained-release formulation of nifedipine in essential hypertensive patients

The authors studied the antihypertensive effect and tolerability of a new sustained‐release formulation of nifedipine 50 mg once a day, in comparison with nifedipine retard 20 mg twice a day in patients with mild or moderate primary arterial hypertension. Both treatments significantly lowered blood pressure with no difference in daily blood pressure profile. At steady state, the two drugs determined comparable plasma levels of nifedipine as measured immediately before the morning dose. After a 12‐month treatment, the new formulation of nifedipine still displayed satisfactory blood pressure control in both supine and standing positions, with no change in tolerability throughout the study. In conclusion, this new sustained‐release formulation of nifedipine has similar efficacy and tolerability to conventional treatment with nifedipine retard 20 mg twice a day.

Beyond waist circumference in an adult male population of Southern Italy: Is there any role for subscapular skinfold thickness in the relationship between insulin-like growth factor-I system and metabolic parameters?

Background: Apart from waist circumference, other adiposity measures, such as subscapular skin fold (SST), arouse growing interest due to their relationship to metabolic complications and cardiovascular risk. The IGF-I system is deregulated in obese subjects in proportion to their degree of visceral adiposity. Aim: To examine the association among IGF-I, IGF-binding protein (BP)-1 and -3 levels and different measures of adiposity in a sample of adult male population in Southern Italy. Materials and methods: A complete database for this analysis was available for 229 (age range 50–82 yr) participating at 2002–2004 Olivetti Heart Study follow-up. Results: After adjustment for age, IGF-I was inversely associated with body mass index (BMI) and waist circumference (p<0.05). IGFBP-1 was inversely associated with BMI, waist circumference, SST, homeostasis model assessment (HOMA) index, fat mass. HOMA index, age, and SST significantly predicted the IGFBP-1 plasma levels, with 24% of IGFBP-1 variability explained at a linear regression analysis. Conclusions: IGFBP-1 inversely correlated to adiposity and HOMA index. Among adiposity indexes, SST was the best predictor of IGFBP-1 levels. The evaluation of some components of the IGF system, and simple measures of body adiposity, such as SST, may represent a further tool to better evidence phenotype profiles associated to the pathogenetic mechanism of cardiovascular risk factor clustering in male adults.

Characteristic Clinical and Biochemical Profile of Recurrent Calcium-Oxalate Nephrolithiasis in Patients with Metabolic Syndrome

Metabolic syndrome is a risk factor for nephrolithiasis. This study was performed to evaluate the clinical and biochemical profile of calcium-oxalate nephrolithiasis in stone formers with metabolic syndrome. A total of 526 recurrent stone formers, 184 of them with metabolic syndrome, and 214 controls were examined. Stone formers with metabolic syndrome showed higher sodium excretion [mean (95% confidence interval), 196 (176–218) vs 160 (150–168) mmol/24h; p<0.01] and lower citrate excretion [2.23 (1.99–2.58) vs 2.84 (2.51–3.17) mmol/24 h; p<0.01] compared to controls, whereas stone formers without metabolic syndrome showed higher calcium and oxalate excretion [5.43 (5.01–5.82) vs 3.58 (2.84–4.19) and 0.34 (0.32–0.36) vs 0.26 (0.20–0.31) mmol/24h for calcium and oxalate, respectively; p<0.01] and lower citrate excretion [2.18 (1.98–2.38) vs 2.84 (2.51–3.17) mmol/24 h; p<0.01] compared to controls. The biochemical profiles was significantly different between stone formers with metabolic syndrome and those without. Dietary habits play a central role in the pathogenesis of nephrolithiasis in stone formers with metabolic syndrome.

Revisione critica della letteratura internazionale di pertinenza internistica prodotta nel biennio 2007-2008 sul tema della nefrolitiasi

ultimi decenni, è possibile identificare in obesità viscerale, dislipidemia, alterazioni del metabolismo glucidico ed ipertensione arteriosa i suoi elementi clinici costitutivi (2). La coesistenza di questi fattori metabolici incrementa in maniera esponenziale il rischio di comparsa di diabete, malattie cardiovascolari ed insufficienza renale cronica, oltre a determinare un aumento significativo del rischio di mortalità per ogni causa (1, 2). Negli anni precedenti al biennio in esame, studi di popolazione avevano dimostrato un’associazione significativa tra alcuni degli elementi clinici costitutivi la sindrome metabolica, in particolare l’obesità, l’iperglicemia e l’ipertensione arteriosa, e la prevalenza di nefrolitiasi e/o l’escrezione urinaria dei fattori di rischio metabolici ad essa associati (3-8). Non erano tuttavia disponibili dati riguardo la possibile associazione tra sindrome metabolica in quanto tale e la nefrolitiasi. Due diversi studi trasversali pubblicati nel corso dell’anno 2008 hanno dimostrato l’esistenza di questa associazione (9, 10). In entrambi i casi la diagnosi di sindrome metabolica è stata formulata secondo i criteri dell’American Heart Association/National Heart, Lung, and Blood Institute (2). In pratica, sono stati considerati affetti da sindrome metabolica tutti i soggetti che presentavano la coesistenza di almeno tre dei seguenti criteri: 1) circonferenza addominale ≥102 cm negli uomini e ≥88 cm nelle donne; 2) livelli sierici di trigliceridi >150 mg/dL (>1.7 mmol/L) o terapia in atto per ipertrigliceridemia; 3) livelli sierici di HDL-colesterolo <40 mg/dL (<1.03 mmol/L) negli uomini e <50 mg/ dL (<1.3 mmol/L) nelle donne o terapia in atto per bassi livelli sierici di HDL-colesterolo; 4) pressione arteriosa sistolica ≥130 mmHg e/o pressione arteriosa diastolica Premessa

ROLE OF DIFFERENT METABOLIC SYNDROME COMPONENTS ON THE RISK TO DEVELOP SLEEP APNOEA: PP.32.275

Objective: In various clinical studies, apnoea sleep disorders have been associated with different cardiovascular and metabolic abnormalities. The aim of this analysis was to assess the relation between a multivariable apnoea prediction index, metabolic syndrome (MS) and its single components in an unselected sample of adult male population. Design and Method: The relationship between MS (AHA 2005 criteria) and a high apnoea risk (HAR) evaluated by a multivariable apnoea prediction index higher than 0.5, was investigated in 612 (mean age ± SD = 59.7 ± 6.4 years) participants at the 2002–04 Olivetti Heart Study follow-up. Results: The prevalence of MS and of HAR were respectively 36.6% (n = 224) and 60.8% (n = 372). MS and HAR were strongly associated (χ2 = 26.3; p < 0.0001). The prevalence of HAR increased gradually with increasing number of MS components. (χ2 = 36.4; p < 0.0001), the higher the MS score, the higher the prevalence of HAR. Using a logistic regression analysis with apnoea risk as dependent variable and MS components and age as independent factors, hypertension (blood pressure > 130/85 mmHg or treatment) and central adiposity (waist circumference > 102 cm) remained the only determinants of HAR with odds ratio (95%CI) of respectively 2.57 (1.53 to 4.33) and 3.84 (2.47 to 5.98). Conclusion: In this sample of adult male population the prevalence of high apnoea risk was related to both presence and severity of metabolic syndrome. Among different components of MS, blood pressure and central adiposity were the factors more strongly associated to the risk to be affected by sleep apnoea disturbances.

PROXIMAL SODIUM REABSORPTION IS AN INDEPENDENT PREDICTOR OF HYPERTENSION: 2D.05

Objective: Given the association between salt-sensitivity of blood pressure (BP) and risk of future hypertension (HPT), we investigated the predictive role of alterations in segmental renal tubular sodium handling in the development of HPT during the 8 year follow-up of the Olivetti Heart Study participants. Methods: A selected sample (n = 314) of OHS population was examined at baseline and after 8 years. The participants were included if they were normotensive (SBP/DBP <140/90 mm Hg without anti-hypertensive treatment) and had normal renal function (creatinine clearance - CrCl> 60 ml/min) at baseline. Proximal and distal fractional tubular sodium reabsorption were calculated using the clearance of exogenous lithium. Results: The baseline sample characteristics were: age 49.3 ± 6.8 yrs, BMI 26.4 ± 2.8 kg/m2, SBP/DBP 119.8 ± 9.6/78.9 ± 6.4 mm Hg, CrCl 90.9 ± 18.2 mL/min (M ± SD). The HPT incidence in 8 years was 52%. The participants who developed HPT (group A) compared with those who did not (group B) had higher baseline SBP (122.4 ± 8.4 mm Hg vs 117.0 ± 10.0, p < 0.0001), DBP (80.6 ± 5.6 VS 77.1 ± 6.7 mm Hg, p < 0.0001), BMI (27.0 ± 2.9 vs 25.9 ± 2.6 kg/m2, p < 0.0001) and fractional proximal reabsorption of sodium (75.8 ± 6.3 vs 73.8 ± 7.3 %, p = 0.01). At logistic regression analysis using standardised variables, a 1SD-higher proximal sodium reabsorption at baseline predicted a 44% greater risk of HPT in 8 years (95% C.I. 13–84, p = 0.003), independently of baseline SBP (OR: 1.88, 95% C.I. 1.43–2.47, p < 0.001), BMI (OR: 1.51, 95% C.I. 1.16–1.95, p = 0.002), age and creatinine clearance used as an index of glomerular filtration rate. Conclusions: In this sample of healthy adult male population, proximal sodium reabsorption indexed to glomerular filtration rate was an independent predictor of future HPT.

SERUM URIC ACID PREDICTS THE DEVELOPMENT OF HYPERTENSION IN A SAMPLE OF MALE NORMOTENSIVE ADULTS: 1B.07

Objective: Cross-sectional and prospective studies showed that serum uric acid levels (SUA) and hypertension (HPT) are related. Our aim was to evaluate this relationship in a sample of healthy male adults, during an 8 year follow-up, in the Olivetti Heart Study. Methods: The population sample was made of 253 participants (mean age 49.5 years, range 26–71) examined both at the beginning (1994–95) and at the end of follow-up (2002–04). The participants were included in the analysis if at baseline they were non-diabetic, normotensive, not on pharmacological treatment for HPT, they had blood pressure (BP) less than 130/85 mmHg and normal renal function (creatinine clearance – CrCl > 60 ml/min). Results: Baseline SUA was directly related to BMI (r = 0.27; p < 0.0001), diastolic BP (r = 0.22; p < 0.0001) and HOMA index (r = 0.28; p < 0.0001) and inversely related to CrCl (r = −0.14; p = 0.02). The incidence of HPT (BP> = 140 and/or 90 mmHg or anti-hypertensive treatment) over 8 years was 45%. The participants who developed HPT had higher basal SUA compared with participants who did not (M ± SE: 5.76 ± 0.11 vs 5.36 ± 0.09 mg/dL; p = 0.006). Logistic regression analysis showed that standardised basal SUA significantly predicted the risk to develop HPT during 8 years (for 1SD higher SUA: OR = 1.40, 95% C.I. 1.06 to 1.86, p = 0.018), after adjustement for age, BMI, SBP, CrCl and HOMA index at baseline. Conclusions: This study revealed the predictive role of SUA on the development of hypertension in previously non diabetic normotensive subjects with normal renal function.