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Nathan Goodyear

alpha-Lipoic acid and ascorbate prevent LDL... [Mol Cell Biochem. 2008] - PubMed - NCBI - 0 views

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    Alpha lipoic acid and vitamin C shown to protect against oxidized LDL.  When discussing the negative effects of LDL, the real risk associated with LDL is whether it is oxidized or not.  Alpha lipoic acid and Vitamin C prevent this and thus protect the vascular endothelium.
Nathan Goodyear

Pathway Central: LDL Oxidation in Atherogenesis - 0 views

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    Great diagram.  This diagram shows the current knowledge of how plaque is formed in arteries.  The major point here is the oxidation of LDL and the activation of the innate immune system and resultant inflammatory signaling.  In the vast majority of cases, the inflammation is driving this process, not the LDL.
Nathan Goodyear

Positive effects of astaxanthin on lipid profiles and oxidative stress in overweight su... - 0 views

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    Astaxanthin at 20 mg found to reduce oxidized LDL and other oxidative stress biomarkers as assessed by Malondialdehydy, SOD, Isoprostane, and TAC.  The dose was 20 mg for 12 weeks. This higher dose was associated with minimal side effects--red stools.
Nathan Goodyear

Understanding lipoproteins as transporters of cholesterol and other lipids - 0 views

  • the density of each lipoprotein is clearly in a constant state of flux
  • Two lipoprotein fractions are primarily involved in transport of lipid to peripheral tissues, very low density lipoproteins (VLDL) from the liver and chylomicrons from the intestinal tract
  • As lipid is removed from these two fractions, the density of each fraction increases, thereby transforming VLDL into intermediate-density lipoprotein (IDL) and ultimately LDL, and chylomicrons into chylomicron remnants
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  • LDL-cholesterol has been described, and overly simplified, as “bad cholesterol” and HDL-cholesterol as “good cholesterol.”
  • HDL, is primarily involved in returning lipid, largely cholesterol, to the liver in a process called reverse cholesterol transport
  • Two primary subfractions of HDL have been classified as the higher-density HDL3, and the less dense, more lipid-filled HDL2
  • Recent investigations are also suggesting that smaller, denser lipoproteins are associated with increased risk of atherosclerotic development
  • lipoproteins as transporters of lipid
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    Brief, but good review of lipoproteins and apoliproteins.
Nathan Goodyear

Lipoprotein(a) as a cardiovascular risk factor: current status - 0 views

  • Lipoprotein(a) is a plasma lipoprotein consisting of a cholesterol-rich LDL particle with one molecule of apolipoprotein B100 and an additional protein, apolipoprotein(a)
  • Elevated Lp(a) levels can potentially increase the risk of CVD (i) via prothrombotic/anti-fibrinolytic effects as apolipoprotein(a) possesses structural homology with plasminogen and plasmin but has no fibrinolytic activity and (ii) via accelerated atherogenesis as a result of intimal deposition of Lp(a) cholesterol, or both
  • evidence suggests that apolipoprotein(a) adducts extracellularly and covalently to apolipoprotein B100-containing lipoproteins, predominantly LDL
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  • Lp(a) is relatively refractory to both lifestyle and drug intervention.
  • Other agents reported to decrease Lp(a) to a minor degree (<10%) include aspirin, l-carnitine, ascorbic acid combined with l-lysine, calcium antagonists, angiotensin-converting enzyme inhibitors, androgens, oestrogen, and its replacements (e.g. tibolone), anti-estrogens (e.g. tamoxifen), and thyroxine replacement in hypothyroid subjects
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    full article on the previously posted abstract on Lp(a).  
Nathan Goodyear

Nutrition Journal | Full text | A daily glass of red wine associated with lifestyle cha... - 0 views

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    tools for health are all around us.  red wine reduced the LDL/HDL ratio by 13% in patients with carotid arteriosclerosis.  This occurred  independently from dietary changes and exercise.
Nathan Goodyear

Metabolic effects of testosterone replacement therapy on hypogonadal men with type 2 di... - 0 views

  • up to 40% of men with T2DM have testosterone deficiency
  • Among diabetic patients, a reduction in sex hormone binding globulin levels induced by insulin resistance leads to a further decline of testosterone levels
  • low bioavailable testosterone concentration was related to decreased lean body mass and muscle strength
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  • Testosterone deficiency has a high prevalence in men with T2DM, and it is also associated with impaired insulin sensitivity, increased percentage body fat, central obesity, dyslipidemia, hypertension and cardiovascular diseases (CVD)
  • A meta-analysis of four randomized controlled trials (RCTs) showed that TRT seemed to improve glycemic control as well as fat mass in T2DM subjects with low testosterone levels and sexual dysfunction.
  • testosterone administration could increase muscle mass and strength
  • Insulin stimulates glucose uptake into muscle and adipose tissue via the Glut4 glucose transporter isoform. When insulin activates signaling via the insulin receptor, Glut4 interacts with insulin receptor substrate 1 to initialize intracellular signaling and facilitate glucose transportation into the cell
  • The benefits of TRT on glucose metabolism can mainly be explained by its influence on the insulin signaling pathway
  • Insulin resistance as assessed by, which is calculated from the equation (If*Gf/22.5, where If is fasting insulin and Gf is fasting glucose), was definitely improved by TRT after testosterone administration in three studies
  • Testosterone was observed to elevate the expression levels and stimulate translocation of Glut4 in cultured skeletal muscle cells and to upregulate Glut4 by activating insulin receptor signaling pathways in neonatal rats
  • These effects were inhibited by a dihydrotestosterone (DHT) blocker, indicating that glucose uptake may correlate with conversion of testosterone to DHT and activation of the androgen receptor.
  • TRT reduced triglyceride levels
  • TRT has been reported to have a positive effect in the decrease of total and LDL cholesterol levels and triglycerides in hypogonadal men
  • a recent meta-analysis showed that statins could significantly lower testosterone concentrations.
  • Epidemiological studies have found a negative relationship between testosterone levels and typical cardiovascular risk markers, such as body mass index, waist circumference, visceral adiposity and carotid intima-media thickness.
  • Testosterone treatment was shown to raise hemoglobin, hematocrit and thromboxane, all of which might give rise to CVD
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    Low Testosterone is a very significant problem in men with type II Diabetes.  Estimated to reach 40%, likely much higher.  They based these estimates only on T levels and sexual symptoms. Testosterone improves glycemic control primarily through Increased transcription and transloction of GLUT4 insulin receptors to the cell surface.  Inflammation reduction is also a mechanism.  Testosteorne lowers Triglycerides in the traditional lipid profile.  Studies are mixed on the other aspects of  lipids.  
Nathan Goodyear

Testosterone Deficiency, Cardiac Health, and Older Men - 0 views

  • Studies have shown pharmacological doses of testosterone to relax coronary arteries when injected intraluminally [39] and to produce modest but consistent improvement in exercise-induced angina and reverse associated ECG changes [40]. The mechanism of action is via blockade of calcium channels with effect of similar magnitude to nifedipine
    • Nathan Goodyear
       
      This directly refutes the recent studies (3) that Testosterone therapy increases cardiovascular events.
    • Nathan Goodyear
       
      Testosterone acts as a calcium channel blocker inducing vasodilation.
  • men with chronic stable angina pectoris, the ischaemic threshold increased after 4 weeks of TRT and a recent study demonstrates improvement continuing beyond 12 months [
  • Exercise capacity in men with chronic heart failure increased after 12 weeks
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  • Studies have shown an inverse relationship between serum testosterone and fasting blood glucose and insulin levels
  • Medications such as chronic analgesics, anticonvulsants, 5ARIs, and androgen ablation therapy are associated with increased risk of testosterone deficiency and insulin resistance
  • Women with T2D or metabolic syndrome characteristically have low SHBG and high free testosterone
    • Nathan Goodyear
       
      This stands in polar opposite of that with men.
  • Hypogonadism is a common feature of the metabolic syndrome
  • The precise interaction between insulin resistance, visceral adiposity, and hypogonadism is, as yet, unclear but the important mechanisms are through increased aromatase production, raised leptin levels, and increase in inflammatory kinins
  • levels of testosterone are reduced in proportion to degree of obesity
  • Men should be encouraged to combine aerobic exercise with strength training. As muscle increases, glucose will be burned more efficiently and insulin levels will fall. A minimum of 30 minutes exercise three times weekly should be advised
  • Testosterone increases levels of fast-twitch muscle fibres
  • By increasing testosterone, levels of type 2 fibres increase and glucose burning improves
  • Weight loss will increase levels of testosterone
  • studies now clearly show that low testosterone leads to visceral obesity and metabolic syndrome and is also a consequence of obesity
  • In the case of MMAS [43], a baseline total testosterone of less than 10.4 nmol/L was associated with a greater than 4-fold incidence of type 2 diabetes over the next 9 years
  • There is high level evidence that TRT improves insulin resistance
  • Low testosterone predicts increased mortality and testosterone therapy improves survival in 587 men with type 2 diabetes
  • A similar retrospective US study involved 1031 men with 372 on TRT. The cumulative mortality was 21% in the untreated group versus 10% ( ) in the treated group with the greatest effect in younger men and those with type 2 diabetes
  • the presence of ED has been shown to be an independent risk factor, particularly in hypogonadal men, increasing the risk of cardiac events by over 50%
  • A recent online publication on ischaemic heart disease mortality in men concluded optimal androgen levels are a biomarker for survival
  • inverse associations between low TT or FT (Table 2) and the severity of CAD
  • A recent 10 year study from Western Australia involving 3690 men followed up from 2001–2010 concluded that TT and FT levels in the normal range were associated with decreased all-cause and cardiovascular mortality, for the first time suggesting that both low and DHT are associated with all-cause mortality and higher levels of DHT reduced cardiovascular risk
  • TDS is associated with increased cardiovascular and all-cause mortality
  • The effect of treatment with TRT reduced the mortality rate of treated cohort (8.4%) to that of the eugonadal group whereas the mortality for the untreated remained high at 19.2%
  • hypogonadal men had slightly increased triglycerides and HDL
  • Men with angiographically proven CAD (coronary artery disease) have significantly lower testosterone levels [29] compared to controls ( ) and there was a significant inverse relationship between the degree of CAD and TT (total testosterone) levels
  • TRT has also been shown to reduce fibrinogen to levels similar to fibrates
  • men treated with long acting testosterone showed highly significant reductions in TC, LDL, and triglycerides with increase in HDL, associated with significant reduction in weight, BMI, and visceral fat
  • Low androgen levels are associated with an increase in inflammatory markers
  • In the Moscow study, C-reactive protein was reduced by TRT at 30 weeks versus placebo
  • In some studies, a decline in diastolic blood pressure has been observed, after 3–9 months [24, 26] and in systolic blood pressure
  • A decline was noted in IL6 and TNF-alpha
  • No studies to date show an increase in LUTS/BPH symptoms with higher serum testosterone levels
  • TRT has been shown to upregulate PDE5 [65] and enhance the effect of PDE5Is (now an accepted therapy for both ED and LUTS), it no longer seems logical to advice avoidance of TRT in men with mild to moderate BPH.
    • Nathan Goodyear
       
      What about just starting with normalization of Testosterone levels first.
  • Several meta-analyses have failed to show a link between TRT and development of prostate cancer [66] but some studies have shown a tendency for more aggressive prostate cancer in men with low testosterone
    • Nathan Goodyear
       
      And if one would have looked at their estrogen levels, I guarantee they would have been found to be elevated.
  • low bioavailable testosterone and high SHBG were associated with a 4.9- and 3.2-fold risk of positive biopsy
  • Current EAU, ISSAM, and BSSM guidance [1, 2] is that there is “no evidence TRT is associated with increased risk of prostate cancer or activation of subclinical cancer.”
  • Men with prostate cancer, treated with androgen deprivation, develop an increase of fat mass with an altered lipid profile
  • Erectile dysfunction is an established marker for future cardiovascular risk and the major presenting symptom leading to a diagnosis of low testosterone
Nathan Goodyear

Using Apolipoprotein B to Manage Dyslipidemic Patients: Time for a Change? - 0 views

  • Apo B is a key structural component of all the atherogenic lipoprotein particles, including LDL, VLDL, and IDL
  • Each of these atherogenic particles carries only one apo B molecule; thus, the total apo B level represents the total number of circulating atherogenic lipoprotein particles and provides the clinician a more accurate picture of a patient's risk of cardiovascular events
  • apo B include the fact that it does not require a fasting specimen
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    good review of lipoproteins.
Nathan Goodyear

Pomegranate juice inhibits oxidized LDL uptake and cholesterol biosynthesis in macropha... - 0 views

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    Pomegranate inhibited foam cell avtivity and uptake of oxLDL
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